# TopoGEN: Preeminent Cancer Research Products Including High Quality Topoisomerase Enzymes & DNA Gyrase > TopoGEN is a biotech CRO that has been providing cancer research products, including Topoisomerase Enzymes and DNA Gyrase since 1991. ## Pages - [dna-gyrase-faq](https://topogen.com/dna-gyrase-faq/) - [test](https://topogen.com/test-2/) - [DNA Repair Kits Based on Transient Transfections: For use in your specific cell line model.](https://topogen.com/dna-repair-kits-based-on-transient-transfections/) - [Kit Replenishments](https://topogen.com/kit-replenishments/) - [TDP1 PRODUCTS](https://topogen.com/tdp1-products/) - [Checkout](https://topogen.com/checkout/) - [Our Distributors](https://topogen.com/distributors/) - [DNA NonRepair](https://topogen.com/dna-nonrepair/) - [DNA Repair](https://topogen.com/dna-repair-kits/) - [Cart](https://topogen.com/cart-2/) - [My Account New](https://topogen.com/my-account-2/) - [KITS](https://topogen.com/kits-2/) - [PRODUCTS](https://topogen.com/products-2/) - [Topo Antibodies](https://topogen.com/topo-antibodies-2/) - [Topo Related Drugs & Assay Reagents](https://topogen.com/topo-related-drugs-assay-reagents/) - [TPD I,II Products](https://topogen.com/tpd-iii-products-2/) - [MOBILE TRANSIENT ASSAY DNA REPAIR SYSTEMS](https://topogen.com/mobile-transient-assay-dna-repair-systems/) - [NON-HOMOLOGOUS END JOINING REPORTER CELLS](https://topogen.com/non-homologous-end-joining-reporter-cells/) - [HOMOLOGOUS RECOMBINATION REPORTER CELLS](https://topogen.com/homologous-recombination-reporter-cells/) - [GYRASE AND TOPO IV](https://topogen.com/gyrase-and-topo-iv/) - [TOPO II](https://topogen.com/topo-ii/) - [TOPO I](https://topogen.com/topo-i/) - [PROTEIN MW MARKERS](https://topogen.com/protein-mw-markers/) - [ANTIBODY KITS](https://topogen.com/antibody-kits/) - [TOPO III ANTIBODIES](https://topogen.com/topo-iii-antibodies/) - [TOPO II ANTIBODIES](https://topogen.com/topo-ii-antibodies/) - [TOPO I ANTIBODIES](https://topogen.com/topo-i-antibodies/) - [CELL CONTEXT DNA REPAIR](https://topogen.com/cell-context-dna-repair-2/) - [TOPO RELATED DRUGS](https://topogen.com/topo-related-drugs/) - [TDP2 PRODUCTS](https://topogen.com/tdp2-products/) - [DNA SUBSTRATES](https://topogen.com/dna-substrates/) - [TOPO ANTIBODIES](https://topogen.com/topo-antibodies/) - [DRUG SCREENING KITS](https://topogen.com/drug-screening-kits/) - [TOPO KITS](https://topogen.com/topo-kits/) - [DNA GYRASES](https://topogen.com/dna-gyrases/) - [TOPO ENZYMES](https://topogen.com/topo-enzymes/) - [My Account](https://topogen.com/my-account/) - [Product & Shipping](https://topogen.com/product-shipping/) - [Blog](https://topogen.com/blog/) - [Store Locator](https://topogen.com/storelocator/) - [test](https://topogen.com/test/) - [Sample Page](https://topogen.com/sample-page/) - [Home](https://topogen.com/) - [About Our Group](https://topogen.com/about-our-group/) - [Contact](https://topogen.com/contact/) - [Research](https://topogen.com/research/) - [Project](https://topogen.com/project/) - [Team](https://topogen.com/team/) - [TopoGEN Solutions Guide](https://topogen.com/topogen-solutions-guide/) - [VENTURES&ALLIANCES](https://topogen.com/venturesalliances/) - [Human topo in vitro screen](https://topogen.com/human-topo-in-vitro-screen/) - [Cell context topo](https://topogen.com/cell-context-topo/) - [Bio-Correlations in Clinical Trials](https://topogen.com/bio-correlations-in-clinical-trials/) - [Western Blotting](https://topogen.com/western-blotting/) - [Quantify Topo Activity Levels In Crude Extracts](https://topogen.com/quantify-topo-activity-levels-2/) - [Topo Genomic DNA](https://topogen.com/topo-genomic-dna-2/) - [Bacterial Grase & Topo IV Screens](https://topogen.com/bacterial-grase-topo-iv-screens/) - [FAQs](https://topogen.com/faqs/) - [Services Quote Form](https://topogen.com/services-quote-form/) - [Technical Procedures](https://topogen.com/technical-procedures/) - [NEWS](https://topogen.com/news/) - [Publications](https://topogen.com/publications/) - [JOBS & INTERNSHIPS](https://topogen.com/jobs-internships/) - [Terms & Conditions](https://topogen.com/terms-conditions/) - [Distributors](https://topogen.com/distributors-3/) - [In situ Screen (cell context) Screening](https://topogen.com/in-situ-screen-cell-context-screening/) - [Reviews & Articles](https://topogen.com/reviews-articles/) - [Topo Genomic DNA Complexes](https://topogen.com/topo-genomic-dna-complexe/) - [Cart](https://topogen.com/cart/) - [Shop](https://topogen.com/shop/) - [Contract Research](https://topogen.com/contract-research/) - [REAGENTS](https://topogen.com/products/reagents/) - [ALL ENZYMES](https://topogen.com/products/all-enzymes/) - [DRUG SCREEN KITS](https://topogen.com/products/drug-screen-kits/) - [KITS](https://topogen.com/kits/) - [PRODUCTS](https://topogen.com/products/) ## Products - [Non-Homologous End Joining (NHEJ) Repair Reporter Kit (Transient Assay-Based Kit)](https://topogen.com/product/non-homologous-end-joining-repair-reporter-kit/) - [Human Topoisomerase I Enzyme](https://topogen.com/product/human-topoisomerase-i-enzyme/) - [10-Hydroxy Camptothecin](https://topogen.com/product/10-hydroxy-camptothecin/) - [<i>Staph aureus</i> DNA Gyrase Enzyme](https://topogen.com/product/s-aureus-dna-gyrase/) - [<i>E. Coli</i> DNA Gyrase Enzyme](https://topogen.com/product/e-coli-dna-gyrase/) - [Topoisomerase II Band Shift Kit](https://topogen.com/product/topoisomerase-ii-band-shift-kit/) - [Topoisomerase II Immunoprecipitation Kit](https://topogen.com/product/topoisomerase-ii-immunoprecipitation-kit/) - [Topoisomerase II Drug Screening Kit (kDNA based)](https://topogen.com/product/topoisomerase-ii-drug-screening-kit-kdna-based/) - [E. coli Topoisomerase IV Enzyme](https://topogen.com/product/e-coli-topoisomerase-iv-enzyme/) - [Homologous Recombination (HR) Repair Reporter Kit (Transient Assay-Based Kit)](https://topogen.com/product/homologous-recombination-repair-reporter-kit/) - [Custom Cell Based Screening Kit for NHEJ](https://topogen.com/product/custom-cell-based-screening-kit-for-nhej-allows-customer-to-create-a-cell-line-host-for-an-nhej-reporter/) - [Custom Cell Based Screening Kit for (HR) Pathway](https://topogen.com/product/custom-cell-based-screening-kit-for-hr-pathway/) - [Mouse: HNCN1.4-Sce NHEJ Reporter Cell line (Includes I-Sce1 Transfection)](https://topogen.com/product/mouse-hncn1-4-sce-nhej-reporter-cell-line-includes-i-sce1-transfection/) - [Mouse:3T3 Fibroblast NHEJ Reporter (Includes I-Sce1 Transfection)](https://topogen.com/product/mouse-3t3-fibroblast-nhej-reporter-cell-line-includes-i-sce1-transfection/) - [Human Neuroblastoma cell HNSH NHEJ Reporter with I-Sce1 DNA](https://topogen.com/product/human-hnsh-nhej-reporter-cell-line-includes-i-sce1-transfection/) - [Human:HeLa NHEJ Reporter Cell Line (Includes I-Sce1 Transfection)](https://topogen.com/product/human-hela-nhej-reporter-cell-line-includes-i-sce1-transfection/) - [Mouse: Neuronal Lineage HR Reporter Cell line (Includes I-Sce1 Transfection)](https://topogen.com/product/mouse-neuronal-lineage-hr-reporter-cell-line-includes-i-sce1-transfection/) - [Mouse: 3T3 HR Reporter Cell Line (Includes I-Sce1 Transfection)](https://topogen.com/product/mouse-3t3-hr-reporter-cell-line-includes-i-sce1-transfection/) - [Human: Neuroblastoma HR Reporter Cell line (SH-SY5Y, Includes I-Sce1 Transfection)](https://topogen.com/product/human-neuroblastoma-hr-reporter-cell-line-sh-sy5y-includes-i-sce1-transfection/) - [Human: HeLa HR Reporter Cell line (Includes CRISPR-CAS Transfection)](https://topogen.com/product/human-hela-hr-reporter-cell-line-includes-crispr-cas-transfection/) - [Human: HeLa Reporter Cell Line (Includes I-Sce1 Transfection)](https://topogen.com/product/human-hela-reporter-cell-line-includes-i-sce1-transfection/) - [Tyrosyl DNA Phosphodiesterase 2 (TDP-2) Substrate](https://topogen.com/product/tdp2-substrate/) - [Human TDP-2](https://topogen.com/product/human-tdp-2/) - [Human TDP-2 Assay Kit](https://topogen.com/product/human-tdp-2-assay-kit/) - [Polyclonal Antibody to Human TDP-1](https://topogen.com/product/polyclonal-antibody-to-human-tdp-1/) - [Human TDP-1](https://topogen.com/product/human-tdp-1/) - [TDP-1 Assay Kit](https://topogen.com/product/tdp-1-assay-kit/) - [Mutant Human Topoisomerase I](https://topogen.com/product/mutant-human-topoisomerase-i/) - [Human Topoisomerase IIα Enzyme](https://topogen.com/product/human-topoisomerase-ii-alpha/) - [Doxorubicin (Adriacin)](https://topogen.com/product/doxorubicin-adriacin/) - [Amsacrine (m-AMSA)](https://topogen.com/product/amsacrine-m-amsa/) - [Daunomycin](https://topogen.com/product/daunomycin/) - [Genistein](https://topogen.com/product/genistein/) - [Etoposide (VP16)](https://topogen.com/product/etoposide-vp16/) - [HU-331](https://topogen.com/product/hu-331/) - [Ellipticine](https://topogen.com/product/ellipticine/) - [Ciprofloxacin](https://topogen.com/product/ciprofloxacin/) - [9-Nitro-20 (S) Camptothecin (Rubitecan)](https://topogen.com/product/9-nitro-20-s-camptothecin-rubitecan/) - [Camptothecin](https://topogen.com/product/camptothecin/) - [Irinotecan (CPT-11)](https://topogen.com/product/irinotecan-cpt-11/) - [9-Amino Camptothecin](https://topogen.com/product/9-amino-camptothecin/) - [Topotecan Hydrochloride (Hycamtin)](https://topogen.com/product/topotecan-hydrochloride-hycamtin/) - [Linear kDNA](https://topogen.com/product/linear-kdna/) - [Decatenated kDNA](https://topogen.com/product/decatenated-kdna/) - [Relaxed pHOT-1 Plasmid DNA Substrate](https://topogen.com/product/relaxed-phot-1-dna/) - [Supercoiled pHOT-1 Plasmid DNA Substrate](https://topogen.com/product/supercoiled-phot-1-plasmid-dna-substrate/) - [Kinetoplast DNA (kDNA)](https://topogen.com/product/kinetoplast-dna-kdna/) - [Topoisomerase I Western Blot Marker](https://topogen.com/product/topoisomerase-i-western-blot-marker/) - [Human Topoisomerase II Alpha Molecular Weight Marker](https://topogen.com/product/human-topoisomerase-ii-alpha-molecular-weight-marker/) - [Topoisomerase II Immunoflourescence Kit](https://topogen.com/product/topoisomerase-ii-immunoflourescence-kit/) - [Monoclonal Antibody to Human Topoisomerase III Alpha](https://topogen.com/product/monoclonal-antibody-to-human-topoisomerase-iii-alpha/) - [Polyclonal Antibody to Human Topoisomerase III Beta](https://topogen.com/product/polyclonal-antibody-to-human-topoisomerase-iii-beta/) - [Monoclonal Antibody to Human Topoisomerase II Alpha](https://topogen.com/product/monoclonal-antibody-to-human-topoisomerase-ii-alpha/) - [Polyclonal Antibody to Yeast Topoisomerase II (Serum)](https://topogen.com/product/polyclonal-antibody-to-yeast-topoisomerase-ii-serum/) - [Polyclonal Antibody to Human Topoiosomerase II Beta](https://topogen.com/product/polyclonal-antibody-to-human-topoiosomerase-ii-beta/) - [Polyclonal Antibody to Human Topoisomerase II Alpha](https://topogen.com/product/polyclonal-antibody-to-human-topoisomerase-ii-alpha/) - [Monoclonal Antibody to Human Topoiosomerase II Beta](https://topogen.com/product/monoclonal-antibody-to-human-topoiosomerase-ii-beta/) - [Topoisomerase II Alpha C-Terminal Peptide](https://topogen.com/product/topoisomerase-ii-alpha-c-terminal-peptide/) - [Polyclonal Antibody to Human Topoisomerase I (Scleroderma Patient Serum)](https://topogen.com/product/polyclonal-antibody-to-human-topoisomerase-i-scleroderma-patient-serum/) - [Monoclonal Antibody to Human Topoisomerase I](https://topogen.com/product/monoclonal-antibody-to-human-topoisomerase-i/) - [Polyclonal to Human Topoisomerase I (serum)](https://topogen.com/product/polyclonal-to-human-topoisomerase-i-serum/) - [Potassium Glutamate](https://topogen.com/product/potassium-glutamate/) - [Topoisomerase IV Assay Buffer](https://topogen.com/product/topoisomerase-iv-assay-buffer/) - [Topoisomerase II Dilution Buffer](https://topogen.com/product/topoisomerase-ii-dilution-buffer/) - [Proteinase K](https://topogen.com/product/proteinase-k/) - [E. coli DNA Gyrase Assay Buffer](https://topogen.com/product/e-coli-dna-gyrase-assay-buffer/) - [20% Sarkosyl](https://topogen.com/product/20-sarkosyl/) - [10X Gel Loading Buffer](https://topogen.com/product/10x-gel-loading-buffer/) - [10% Sodium Dodecyl Sulfate](https://topogen.com/product/10-sodium-dodecyl-sulfate/) - [5X Universal Stop Buffer](https://topogen.com/product/5x-universal-stop-buffer/) - [20mM ATP](https://topogen.com/product/20mm-atp/) - [Topoisomerase I Dilution Buffer](https://topogen.com/product/topoisomerase-i-dilution-buffer/) - [Topoisomerase II Assay Buffer](https://topogen.com/product/topoisomerase-ii-assay-buffer/) - [S. Aureus Gyrase Assay Buffer](https://topogen.com/product/s-aureus-gyrase-assay-buffer/) - [Human Topoisomerase ICE Assay Kit](https://topogen.com/product/human-topoisomerase-ice-assay-kit/) - [Topoisomerase I Hi-Loading Inhibition Kit](https://topogen.com/product/topoisomerase-i-hi-loading-inhibition-kit/) - [E. coli DNA Gyrase Drug Screening Kit (Plasmid Based)](https://topogen.com/product/e-coli-dna-gyrase-drug-screening-kit-plasmid/) - [E. coli Topoisomerase IV Drug Screening Kit](https://topogen.com/product/e-coli-topoisomerase-iv-drug-screening-kit/) - [Topoisomerase II Drug Screening Kit](https://topogen.com/product/topoisomerase-ii-drug-screening-kit/) - [TopII-NucEx Kit](https://topogen.com/product/topii-nucex-kit/) - [TopI-NucEx Kit](https://topogen.com/product/topi-nucex-kit/) - [E. coli DNA Gyrase and Relaxed DNA Assay Kit](https://topogen.com/product/e-coli-dna-gyrase-and-relaxed-dna-assay-kit/) - [DNA Intercalator/Unwinding Kit](https://topogen.com/product/dna-intercalator-unwinding-kit/) - [Gyrase Drug Screening Kit (kDNA Based)](https://topogen.com/product/gyrase-drug-screening-kit-kdna/) - [Human Topoisomerase II Assay Kit](https://topogen.com/product/human-topoisomerase-ii-assay-kit/) - [Human Topoisomerase I Assay Kit](https://topogen.com/product/human-topoisomerase-i-assay-kit/) - [Topoisomerase I Drug Screening Kit](https://topogen.com/product/topoisomerase-i-drug-screening-kit/) ## Posts - [Could Boosting DNA Repair Protect Patients from Chemotherapy Side Effects?](https://topogen.com/could-boosting-dna-repair-protect-patients-from-chemotherapy-side-effects/) - [A New Paradigm for Targeting Topoisomerase IIβ](https://topogen.com/a-new-paradigm-for-targeting-topoisomerase-ii%ce%b2/) - [TopoGEN Reagents Enable Discovery of a New Pathway to Selective TOP2β Regulation](https://topogen.com/topogen-reagents-enable-discovery-of-a-new-pathway-to-selective-top2%ce%b2-regulation/) - [New Nature Structural & Molecular Biology Study Reveals How Collapsed Replication Forks Shape Genome Stability](https://topogen.com/new-nature-structural-molecular-biology-study-reveals-how-collapsed-replication-forks-shape-genome-stability/) - [Natural Product Topoisomerase Research Highlights the Power of Mechanistic Enzyme Assays](https://topogen.com/natural-product-topoisomerase-research-highlights-the-power-of-mechanistic-enzyme-assays/) - [Enhancing Gene Delivery Efficiency with DNA Gyrase–Driven Supercoiled DNA](https://topogen.com/enhancing-gene-delivery-efficiency-with-dna-gyrase-driven-supercoiled-dna/) - [New Study Describes How Topoisomerase Inhibitor Promotes Longevity](https://topogen.com/topoisomerase-inhibitor-and-longevity-connection/) - [Natural Products Meet Precision Oncology: A Mechanistic Opportunity for TopoGEN](https://topogen.com/natural-products-are-back-in-oncology-but-this-time-mechanism-matters/) - [Tdp1 Expands Its Role: New Insights into Topoisomerase II Repair Pathways](https://topogen.com/new-insights-into-topoisomerase-ii-repair-pathways-tdp1/) - [Gold(III) Compounds Reveal a Hidden Principle in Topoisomerase Drug Discovery](https://topogen.com/goldiii-compounds-reveal-hidden-principle-in-topoisomerase-drug-discovery/) - [TOP2B: The Hidden Enzyme Behind Cancer-Causing DNA Breaks](https://topogen.com/top2b-the-hidden-enzyme-behind-cancer-causing-dna-breaks/) - [TopoGEN: Making Tomorrow’s Cancer Breakthroughs Possible Today](https://topogen.com/extrachromosomal-circular-dna-ecdna-retained-in-cancer-cells/) - [How Cells Clear TOP1cc Through Autophagy — And Why This Changes the Game for Anti-Cancer Discovery](https://topogen.com/how-cells-clear-top1cc-through-autophagy-and-why-this-changes-the-game-for-anti-cancer-discovery/) - [What a Creepy Looking Rodent Reveals about our Understanding of Longevity](https://topogen.com/naked-mole-rats-dna-repair-and-longevity/) - [Dual-Target Inhibitors of DNA and TOP2A for the Treatment of Triple Negative Breast Cancer](https://topogen.com/dual-target-inhibitors-of-dna-and-top2a-for-the-treatment-of-triple-negative-breast-cancer/) - [Topo I Drug Kit: A Primer](https://topogen.com/topo-i-drug-kit-a-primer/) - [The Story of TopoGEN](https://topogen.com/the-story-of-topogen/) - [Topoisomerases and Cardiotoxicity](https://topogen.com/topoisomerase-ii-and-cardiotoxicity/) - [Transfection-based HR and NHEJ kits: Now Available from TopoGEN](https://topogen.com/transfection-based-dna-repair-kits-hr-nhej/) - [Accelerate Your R&D Output with the New IQ Screen](https://topogen.com/accelerate-your-rd-output-with-the-new-iq-screen/) - [Contract R&D to Identify Drugs that Target Human Topo I, Topo II, Bacterial Topo IV and DNA Gyrase](https://topogen.com/contract-rd-to-identify-drugs-that-target-human-topo-i-topo-ii-bacterial-topo-iv-and-dna-gyrase/) - [Anthracycline drug targeting: cytoplasmic versus nuclear–a fork in the road.](https://topogen.com/anthracycline-drug-targeting-cytoplasmic-versus-nuclear-a-fork-in-the-road/) - [DNA topoisomerase II rescue by catalytic inhibitors: a new strategy to improve the antitumor selectivity of etoposide.](https://topogen.com/dna-topoisomerase-ii-rescue-by-catalytic-inhibitors-a-new-strategy-to-improve-the-antitumor-selectivity-of-etoposide/) - [Topoisomerase I inhibitors: review and update.](https://topogen.com/topoisomerase-i-inhibitors-review-and-update/) - [The use of topoisomerase I inhibitors in multiple myeloma.](https://topogen.com/the-use-of-topoisomerase-i-inhibitors-in-multiple-myeloma/) - [Mechanism of action of camptothecin.](https://topogen.com/mechanism-of-action-of-camptothecin/) - [Dual topoisomerase I/II inhibitors in cancer therapy.](https://topogen.com/dual-topoisomerase-i-ii-inhibitors-in-cancer-therapy/) - [Biological targets of antitumor indolocarbazoles bearing a sugar moiety..](https://topogen.com/biological-targets-of-antitumor-indolocarbazoles-bearing-a-sugar-moiety/) - [The Impact of tumor physiology on camptothecin-based drug development](https://topogen.com/the-impact-of-tumor-physiology-on-camptothecin-based-drug-development/) - [CELL CONTEXT DNA REPAIR KITS NOW AVAILABLE](https://topogen.com/cell-context-dna-repair-kits/) - [Contract R&D to Identify Drugs that Target Human Topo I, Topo II, Bacterial Topo IV and DNA Gyrase](https://topogen.com/contract-rd/) - [SBIR-Funded Alliance to Conquer the Cold-Chain](https://topogen.com/new-age-of-biological-research-that-changed-the-last-decade/) - [Update on the role of topotecan in the treatment of non-small cell lung cancer.](https://topogen.com/update-on-the-role-of-topotecan-in-the-treatment-of-non-small-cell-lung-cancer/) - [Contract R&D to Identify Drugs that Target Human Topo I, Topo II, Bacterial Topo IV and DNA Gyrase](https://topogen.com/contract-research-organization-topogen/) - [Cell Context DNA Repair Kits Now Available](https://topogen.com/cell-context-dna-repair-kits-available-from-topogen/) - [SBIR-Funded Alliance to Conquer the Cold-Chain](https://topogen.com/sbir-funded-alliance-to-conquer-the-cold-chain/) ## Research - [Contract R&D to Identify Drugs that Target Human Topo I, Topo II, Bacterial Topo IV and DNA Gyrase](https://topogen.com/researches/359713/) - [Contract R&D](https://topogen.com/researches/contract-rd/) - [Virtual consultation](https://topogen.com/researches/virtual-consultation/) - [Virtual consultation](https://topogen.com/researches/virtual-consultation-2/) - [Biochemical research](https://topogen.com/researches/biochemical-research/) - [Pathological research](https://topogen.com/researches/pathological-research/) - [Experimental research](https://topogen.com/researches/experimental-research/) - [Pharmaceutical research](https://topogen.com/researches/pharmaceutical-research/) - [Agriculture research](https://topogen.com/researches/agriculture-research/) # # Detailed Content ## Pages Topoisomerase FAQ Expert answers to topoisomerase enzyme, DNA gyrase, topo I/II assay, kDNA substrate, and drug screening questions for cancer and antibacterial research. What is TopoGEN and what does the company specialize in? TopoGEN, Inc. is a 20 year old biotechnology company specializing in DNA topoisomerases, DNA repair enzymes, genotoxicity assays, and mechanism-of-action studies related to cancer therapeutics, antibiotics, and genome stability research. The company provides purified enzymes, biochemical assay kits, cell-based assays, and contract research services to academic, pharmaceutical, and biotech laboratories worldwide. What are TopoGEN’s best-selling products? Some of the most widely used TopoGEN products include:Human Topoisomerase I (human, bacterial)Human Topoisomerase IIα,βBacterical DNA Gyrases (multiple species)Kinetoplast DNA (kDNA) substrates (specific for type 2 enzymes)Relaxed, supercoiled, linear plasmid DNA substratesAll DNA substrates validated and certified to workDNA targets with high affinity topo binding sitesTopoisomerase assay & drug screening kitsValidate topo drugs: certified to workAnti-topo antibodies: fully validated for specific applications (IF, IP, ICE, Westerns, etc)Cell context assays for detecting covalent enzyme-DNA complexes (ICE Bio)Technologies to interrogate topo-DNA damage/repair pathwaysTDP1, TDP2 enzymes for drug discoveryAny topo pathway adjacent genes and gene productsThese products are commonly used in anti-cancer drug discovery, antibiotic development, and DNA damage R&D. What makes TopoGEN different from other enzyme suppliers? TopoGEN focuses specifically on DNA topology, topoisomerases, and DNA repair biology. Unlike general reagent suppliers, the company combines:Deep scientific expertiseProprietary assay systemsCell-based validation platformsCRO servicesHighly cited research productsTechnical consultation from published experts in the topoisomerase fieldTopoGEN also provides mechanism-of-action interpretation, not simply reagents. What is an... Showing 1 – 2 of 2 results Showing all 2 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products DNA Gyrases E. coli DNA Gyrase S. aureus DNA Gyrase Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2000GE. Coli DNA Gyrase EnzymeTopoGEN’s purified E. coli DNA gyrase is widely used as a reliable, mechanistically-informative enzyme system for in vitro supercoiling assays, antibacterial lead screening, and mechanism-of-action classification. Investigators use gyrase assays both to identify compounds that trap cleavage complexes (interfacial poisons) versus those that block catalysis (catalytic inhibitors), enabling faster and more confident triage of antibacterial candidates. Beyond screening, gyrase assays have helped enable discovery of new bacterial control mechanisms, including toxin-driven modifications of type IIA topoisomerases, reinforcing gyrase as a central hub in bacterial viability and stress biology. Read more Select 100 Units — $370. 00500 Units — $700. 001000 Units — $1,100. 002000 Units — $1,800. 00 Max: Min: 1 Step: 1 Add to CartTG2000GSAStaph aureus DNA Gyrase EnzymeHighly purified Staph aureus DNA gyrase... Our DNA Repair Kits use a novel GFP reporter that converts from GFP negative to GFP positive cells through either NHEJ or HR mechanisms. The plasmids are specifically engineered to follow only one of the two major repair paths found in animal cells. Our Kits are extremely flexible and can be applied in several ways. The Kits in described in this collection and very easy and simply to apply. Most labs work in specific cell line models (Lymphoma, Prostate, Pancreatic cells for example) and are interested in testing DNA repair in those model cells. You can take any cell line of choice and simply introduce two key plasmids simultaneously by transient transfection and analyze the resulting positive cells as a means of DNA repair efficiency. This means that you will be testing a pool of cells that each contain the appropriate plasmid DNA's. Any cell in the population that does not receive both reporters will be GFP negative and therefore can be ignored. A major advantage of the system is that the investigator can immediately get the system, running and perform experiments with minimal downtime associated with creating stably transfected cell lines. Details of the reporter construction and mechanism of action are featured in background videos. https://www. youtube. com/watch? v=XeBAICuV0Uc&embeds_referring_euri=https%3A%2F%2Fdnarepairkits. com%2F&source_ve_path=OTY3MTQ Homologous Recombination (HR) Repair Reporter Kit (Transient Assay-Based Kit) Non-Homologous End Joining (NHEJ) Repair Reporter Kit (Transient Assay-Based Kit) Our Services WHY CHOOSE US When you become our customer, we become your partner in research. We review your data... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 13 of 13 results Showing all 13 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products TPD1 Products Human TPD1 Polyclonal AB to Human TDP1 TPD1 Assay Kit Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG406010% Sodium Dodecyl Sulfate High purity SDS is dissolved in triple glass distilled/deionized, sterile water to 10% (w/v). The ability of each lot to function as an effective topoisomerase denaturant is tested and verified for each lot. Read more$95. 00 Max: Min: 1 Step: 1 Add to CartTG403810X Gel Loading Buffer Vial contains 1ml of 10X agarose gel loading buffer ( 0. 005% bromophenol blue, 50% glycerol). Read more$95. 00 Max: Min: 1 Step: 1 Add to CartTG406520% Sarkosyl 20% Sarkosyl Read more$120. 00 Max: Min: 1 Step: 1 Add to CartTG403520mM ATP 20mM ATP supplied in aqueous buffer (0. 5ml). Read more$95. 00 Max: Min: 1 Step: 1 Add to CartTG40375X Universal Stop Buffer Is... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 3 of 3 results Showing all 3 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products TPD1 Products Human TPD1 Polyclonal AB to Human TDP1 TPD1 Assay Kit Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2004HHuman TDP-1 TopoGEN provides purified Human Tyrosyl DNA Phosphodiesterase (Tdp1) purified to homogeneity to a single 68 kDa band on SDS-PAGE. Tdp1 is catalytically active and will remove a terminal 3’ phosphotyrosyl group from a specifically designed oligo target site (oligo-Tyr). Read more Select 250 Units — $375. 00500 Units — $475. 00 Max: Min: 1 Step: 1 Add to CartTG2016Polyclonal Antibody to Human TDP-1 A rabbit polyclonal antibody was prepared against the native Tdp1 protein. The purity was greater than 99% as determined by SDS-PAGE. The antibody is in solution (PBS) at 2. 5 unit/ul (see definitions of unit below). This antibody is ideal for Western blotting applications or immunoflourescent (IF) studies on the cytological... Checkout Shipping Method Payment Information Credit card information is never stored on our servers. Additional information Order notes (optional) WHY CHOOSE US WE ARE DEDICATED TO SUPPORTING YOU TOPOGEN products are available throughout the world via our network of international distributors. Please contact the local distributor for availability, pricing and product support. If your country is not listed, please contact us at our North American office. Thank You! Search by Distributor's name Search Distributor Filter Filter By Country Select a Country AustraliaAustriaCanadaChinaDenmarkFranceGermanyIndiaIsraelItalyJapanKoreaNetherlandsNew ZealandPolandSingaporeSouth AfricaSwitzerlandTaiwanThailandUKUS Address Get my Position Reset all Filters Show all Stores Search in this Area × - TOPOGEN’S - PARTNERS A summary of Non - Homology End Joining Recombination (NHEJ) Repair Kits A summary of Repair Kits based on transfecting either DR - GFP (HR repair) or HN - GFP (NHEJ) reporters and I - Sce1 expression plasmid to make pools of repair reporting cells in any cell line. A summary of Repair Kits based on transfecting either DR - GFP (HR repair) or HN - GFP (NHEJ) reporters and I - Sce1 expression plasmid to make pools of repair reporting cells in any cell line. A summary of HR - DNA Repair Systems: Homologous Recombination (HR) A summary of Non - Homology End Joining Recombination (NHEJ) Repair Kits Dashboard Orders Downloads Addresses Payment methods Account Details Logout Hello Yash Baswani (not Yash Baswani? Log out) From your account dashboard you can view your recent orders, manage your shipping and billing addresses, and edit your password and account details. -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 15 of 43 results Showing all 43 results Showing the single result No results found Category Cell Context DNA Repair Drug Screening Kits Kit Replenishments Topo Kits Download CSV Sort by Sort by Name A - Z Sort by Name Z - A Sort by Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase DR3000-HRHeLa-SceHuman: HeLa Reporter Cell Line (Includes I-Sce1 Transfection) Select 25 Assays — $1,975. 0050 Assays — $2,245. 00125 Assays — $2,795. 00 Max: Min: 1 Step: 1 Add to CartDR3000-HRHeLaHuman: HeLa HR Reporter Cell line (Includes CRISPR-CAS Transfection) Select 25 Assays — $2,085. 0050 Assays — $2,355. 00125 Assays — $2,895. 00 Max: Min: 1 Step: 1 Add to CartDR3000-HRSH-SceHuman: Neuroblastoma HR Reporter Cell line (SH-SY5Y, Includes I-Sce1 Transfection) Select 25 Assays — $2,415. 0050 Assays — $2,685. 00125 Assays — $3,235. 00 Max: Min: 1 Step: 1 Add to CartDR3000-HR3T3-SceMouse: 3T3 HR Reporter Cell Line (Includes I-Sce1 Transfection) Select 25 Assays — $1,975. 0050 Assays — $2,245. 00125 Assays — $2,795. 00 Max: Min: 1 Step: 1 Add to CartDR3000-HRCN1. 4-SceMouse: Neuronal Lineage HR Reporter Cell line (Includes I-Sce1 Transfection) Select 25 Assays — $2,415. 0050 Assays — $2,685. 00125 Assays — $3,235. 00 Max: Min: 1 Step: 1 Add to CartDR3000Custom Cell Based Screening Kit for (HR) Pathway Select Custom Screening 1, 25 Assays — $2,415. 00Custom Screening 2, 50 Assays — $2,685. 00Custom Screening 3, 125 Assays — $3,235. 00Custom... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – -1 of 87 results Showing all 87 results Showing the single result No results found Category Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits TDP1 Products Topo Antibodies Topo Enzymes Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Sort by Name A - Z Sort by Name Z - A Sort by Filters Sort results Reset Apply Product IDProduct InfoDescription DR3000-HRHeLaHuman: HeLa HR Reporter Cell line (Includes CRISPR-CAS Transfection)DRT5050Non-Homologous End Joining (NHEJ) Repair Reporter Kit (Transient Assay-Based Kit) This is a plasmid transfection based reporter system designed to allow the customer to screen or examine any agent that affects the process of NHEJ DNA repair. It will work in most of all cell lines that can be transfected. The kit uses GFP as an in vivo readout for NHEJ and includes two Plasmids... Show more (+) This is a plasmid transfection based reporter system designed to allow the customer to screen or examine any agent that affects the process of NHEJ DNA repair. It will work in most of all cell lines that can be transfected. The kit uses GFP as an in vivo readout for NHEJ and includes two Plasmids that are validated as high quality, transfection-grade DNA. Show less (-) DR3050Homologous Recombination (HR) Repair Reporter Kit (Transient Assay-Based Kit) This is a custom cell-based reporter system designed to allow researchers to study homologous recombination (HR) in a cell... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 15 of 16 results Showing all 16 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Topo Antibodies Antibody Kits Protein MW Markers Topoisomerase I Antibodies Topoisomerase II Immunoflourescence Kit Topoisomerase III Antibodies Topoisosomerase II Antibodies Download CSV Sort by Sort by Name A - Z Sort by Name Z - A Sort by Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2012-2Polyclonal to Human Topoisomerase I (serum)$355. 00 Max: Min: 1 Step: 1 Add to CartTG2012-4Monoclonal Antibody to Human Topoisomerase I$355. 00 Max: Min: 1 Step: 1 Add to CartTG2012Polyclonal Antibody to Human Topoisomerase I (Scleroderma Patient Serum)$355. 00 Max: Min: 1 Step: 1 Add to CartTG2011-2Topoisomerase II Alpha C-Terminal Peptide$375. 00 Max: Min: 1 Step: 1 Add to CartTG2011-1Polyclonal Antibody to Human Topoisomerase II Alpha$355. 00 Max: Min: 1 Step: 1 Add to CartTG2010-1Monoclonal Antibody to Human Topoisomerase II Alpha$355. 00 Max: Min: 1 Step: 1 Add to CartTG2010-3Polyclonal Antibody to Human Topoiosomerase II Beta$355. 00 Max: Min: 1 Step: 1 Add to CartTG2014Polyclonal Antibody to Yeast Topoisomerase II (Serum)$355.... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Category DNA Substrates Topoisomerase Related Drugs Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply PRODUCT IDProduct InfoDescriptionPurchase TG410310-Hydroxy Camptothecin$130. 00 Max: Min: 1 Step: 1 Add to CartTG41049-Amino Camptothecin$130. 00 Max: Min: 1 Step: 1 Add to CartTG41029-Nitro-20 (S) Camptothecin (Rubitecan)$130. 00 Max: Min: 1 Step: 1 Add to CartTG4150Amsacrine (m-AMSA)$120. 00 Max: Min: 1 Step: 1 Add to CartTG4110Camptothecin$130. 00 Max: Min: 1 Step: 1 Add to CartTG4180Ciprofloxacin$120. 00 Max: Min: 1 Step: 1 Add to CartTG4130Daunomycin$130. 00 Max: Min: 1 Step: 1 Add to CartTG2020-1Decatenated kDNA$150. 00 Max: Min: 1 Step: 1 Add to CartTG4120Doxorubicin (Adriacin)$95. 00 Max: Min: 1 Step: 1 Add to CartTG4170Ellipticine$130. 00 Max: Min: 1 Step: 1 Add to CartTG4140Etoposide (VP16)$120. 00 Max: Min: 1 Step: 1 Add to CartTG4160Genistein$130. 00 Max: Min: 1 Step: 1 Add to CartTG4200HU-331$145. 00 Max: Min: 1 Step: 1 Add to CartTG4101Irinotecan (CPT-11)$140. 00 Max: Min: 1 Step: 1 Add to CartTG2013Kinetoplast DNA (kDNA) Select 25 ug — $275. 0050 ug — $400. 00250 ug — $980. 00 Max: Min: 1 Step: 1 Add to CartTG2018-1Linear kDNA$150. 00 Max: Min: 1 Step: 1 Add to CartTG2035Relaxed pHOT-1 Plasmid DNA Substrate Relaxed pHOT-1 Plasmid DNA is the ideal substrate for use assaying the supercoiling activity of DNA gyrase. Read More Select 25 ug — $275. 0050 ug — $410. 00250 ug... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Category TDP1 Products TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply PRODUCT IDProduct InfoDescriptionPurchase TG2004HHuman TDP-1 Select 250 Units — $375. 00500 Units — $475. 00 Max: Min: 1 Step: 1 Add to CartTG2003HHuman TDP-2 Select 50 ug — $520. 0025 ug — $420. 00 Max: Min: 1 Step: 1 Add to CartTG1005Human TDP-2 Assay Kit Select 100 Assays — $475. 00250 Assays — $595. 00 Max: Min: 1 Step: 1 Add to CartTG2016Polyclonal Antibody to Human TDP-1$355. 00 Max: Min: 1 Step: 1 Add to CartTG1004TDP-1 Assay Kit Select 100 Assays — $410. 00250 Assays — $495. 00 Max: Min: 1 Step: 1 Add to CartTG2038Tyrosyl DNA Phosphodiesterase 2 (TDP-2) Substrate Select 10 ug — $375. 0050 ug — $475. 00 Max: Min: 1 Step: 1 Add to Cart Edit table Our Services WHY CHOOSE US When you become our customer, we become your partner in research. We review your data and offer valuable input. Feel free to contact us for further information about how we can assist your topoisomerase research endeavors. View Services -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 2 of 2 results Showing all 2 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase DR3050Homologous Recombination (HR) Repair Reporter Kit (Transient Assay-Based Kit)HR DNA Repair Reporter Kit by Plasmid Transfection Assay designed to allow researchers to study Homologous Recombination (HR) in a cell line of their choosing. The kit uses GFP as an in vivo readout for the HR pathway and includes proper controls to set the system up in your own lab. NEW: we are now offering an affordable trial size (50ug each of 3 plasmids in the Kit) to allow you to test the power of our new cell-based kits. We offer academic and for-profit pricing, please contact us for a quote. Read more Select 50 ug — $895. 00250 ug — $3,395. 00500 ug — $4,995. 001000ug — $5,995. 00 Max: Min: 1 Step: 1 Add to CartDRT5050Non-Homologous End... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 4 of 4 results Showing all 4 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase DR5000-CUSTOMCustom Cell Based Screening Kit for NHEJ Custom Cell Based Screening Kit for NHEJ contains reagents necessary to create a complete NHEJ reporter system in any animal cell line. It includes the NHEJ-GFP reporter with a selectable marker and a DS DNA cleavage nuclease to initiate DNA repair. Read more Select 25 Assays (no cell line included) — $1,895. 0050 Assays (no cell line included) — $2,145. 00125 Assays (no cell line included) — $2,645. 0025 Assays — $2,495. 0050 Assays — $2,745. 00125 Assays — $3,245. 00 Max: Min: 1 Step: 1 Add to CartDR5000-HNSH-SceHuman Neuroblastoma cell HNSH NHEJ Reporter with I-Sce1 DNA This is a cell-based reporter kit that is hosted by a human neuroblastoma cell line (SH-SY5Y) that can grow continuously in vitro and will... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 6 of 6 results Showing all 6 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase DR3000Custom Cell Based Screening Kit for (HR) Pathway This kit contains reagents necessary to create a complete HR reporter system in any animal cell line. It includes an HR-GFP reporter with a selectable marker and a DS DNA cleavage nuclease to initiate HR. Because GFP is a neutral gene reporter and not subject to selection, the HR process can easily be examined and assayed by assessing the %GFP or GFP intensity in a population of cells. The system is mobile in that it can be incorporated in any cell lineage or species to adapt to the investigators system of study. Read more Select Custom Screening 1, 25 Assays — $2,415. 00Custom Screening 2, 50 Assays — $2,685. 00Custom Screening 3, 125 Assays — $3,235. 00Custom Screening 1, 25... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 1 of 1 results Showing all 1 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG4180Ciprofloxacin A control poison/inhibitor of DNA Gyrase and Topo IV. This is also included in the Topo IV/Gyrase Drug Screening Kits. Read more$120. 00 Max: Min: 1 Step: 1 Add to Cart Edit table Our Services WHY CHOOSE USWhen you become our customer, we become your partner in research. We review your data and offer valuable input. Feel free to contact us for further information about how we can assist your topoisomerase research endeavors. View Services -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 7 of 7 results Showing all 7 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG4150Amsacrine (m-AMSA) TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase II. For in vitro cleavage detection, we recommend that the drug be tested over a wide range of uM concentrations; however, cleavages are strongly influenced by the amount of topoisomerase in the reaction as well as the type of assay being employed (SDSK+ vs. Radioactive End Labeled DNA vs. testing for plasmid cleavages). Note that large amounts of enzyme will be required to detect cleavage complex, compared to assays that measure catalytic activity. Read more$120. 00 Max: Min: 1 Step: 1 Add to CartTG4130Daunomycin TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase II. Read more$130. 00 Max: Min: 1 Step: 1 Add to CartTG4120Doxorubicin (Adriacin) TopoGEN provides this reagent as a control poison/inhibitor of... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 5 of 5 results Showing all 5 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG410310-Hydroxy Camptothecin10-Hydroxy Camptothecin has shown promising activity against a range of tumour types. This CPT derivative causes cell toxicity by stabilizing a ternary complex between the nuclear enzyme topoisomerase I (topo I) and double-stranded DNA, leading to single and double strand breaks. TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase I. Read more$130. 00 Max: Min: 1 Step: 1 Add to CartTG41049-Amino Camptothecin 9-Amino-20-(R,S)-camptothecin (also known as 9-amino campthecin) is an analogue of camptothecin. Like other CPT congeners, it shows some promising activity against a range of tumor types. This compound causes cell toxicity by stabilizing a ternary complex between the nuclear enzyme topoisomerase I (topo I) and double-stranded DNA, leading to single and double strand breaks. TopoGEN provides this reagent as a control poison/inhibitor of... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 2 of 2 results Showing all 2 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2011-3Human Topoisomerase II Alpha Molecular Weight MarkerThe marker set for topo II is used to unambiguously locate the position of the 170 kDa topo II in Western Blots. The human 170 kDa is present in SDS-PAGE loading buffer. Note that human topo II may break down spontaneously with prolonged storage or with repeated freezing and thawing cycles. TopoGEN, Inc. stipulates that the marker be 90% undegraded at the time of shipment. Read more$375. 00 Max: Min: 1 Step: 1 Add to CartTG2011-4Topoisomerase I Western Blot MarkerThe Western blot marker set for topo I is used to unambiguously locate the position of the 100 kDa form of intact topo I. This product is supplied in SDS-PAGE loading buffer and ready to load directly onto an SDS-PAGE. Read more$375. 00... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 3 of 3 results Showing all 3 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG1024Topoisomerase II Band Shift KitTopoGEN has extensive experience with assays for topoisomerase inhibition in vivo. This analysis allows the investigator to ascertain whether a novel agent is active against endogenous Top2bin whole cells. An important benefit to this analysis is that one can use any tumor cell or tissue in order to establish clinical efficacy against a specific tumor cell line. We use essentially the same basic approach for Topo I, and Topo IIa,b. The kit is based upon ‘band shifting’ in a western blot using mono-specific antibody probes for Top2a (TG1024-A) or Top2b (TG1024-B. This kit can be used to unambiguously detect a Top2a... Read more Select 25 Polyclonal Assays — $475. 0025 Monoclonal Assays — $475. 00 Max: Min: 1 Step: 1 Add to CartTG1030Topoisomerase II... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 2 of 2 results Showing all 2 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2015Monoclonal Antibody to Human Topoisomerase III AlphaThis monoclonal antibody was raised against purified recombinant protein and is specific for the C-terminal region (residues 748-976). The antibody is not ideal for use in western blotting experiments but will work on slot blot applications. It is well suited for immunohistochemistry with paraffin embedded tissue using 1:25 to 150 dilutions, the high temperature unmasking procedure and standard ABC techniques. It will work with frozen tissue although acetone fixation is recommended. We generally recommend 60 min incubation at 25 C for the primary antibody. Specific conditions used in each lab may vary as will specific applications for this AB. For... Read more$375. 00 Max: Min: 1 Step: 1 Add to CartTG2010-4Polyclonal Antibody to Human Topoisomerase III BetaA rabbit polyclonal antibody was prepared... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 6 of 6 results Showing all 6 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2011-5Monoclonal Antibody to Human Topoiosomerase II Beta This mouse monoclonal antibody is directed specifically against purified Topo IIb. Because the two isoforms are very close in MW, we demonstrate by band shifting analysis combined with Westerns that this antibody reacts predictably with the Beta isoform (Fig. 1). Read more$380. 00 Max: Min: 1 Step: 1 Add to CartTG2010-1Monoclonal Antibody to Human Topoisomerase II AlphaMouse monoclonal antibody prepared against an oligopeptide derived from the C-terminus of the p170 kDa human Topoisomerase II Alpha. The antibody was then affinity purified over a column containing the same peptide. Read more$355. 00 Max: Min: 1 Step: 1 Add to CartTG2010-3Polyclonal Antibody to Human Topoiosomerase II BetaThis rabbit polyclonal antibody is directed specifically against the C-terminus of purified topo IIb. Read more$355. 00... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 3 of 3 results Showing all 3 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2012-4Monoclonal Antibody to Human Topoisomerase I This monoclonal antibody was raised to human topo I (TG2005H-RC1) using standard methods. The antibody (IgG class) works very well for Western blotting experiments. The epitope has not been mapped. This product has not been tested for IP or IF applications; however, given the high specificity seen on Westerns, it should work well in these applications. Read more$355. 00 Max: Min: 1 Step: 1 Add to CartTG2012Polyclonal Antibody to Human Topoisomerase I (Scleroderma Patient Serum) The immunoglobulin fraction was purified from scleroderma patients and shown to react specifically with the 100 kDa form of Topo I using Western blotting. The antibody is particularly useful as a Western blotting probe and can be used at high dilutions (>1:5,000). Cross reactivity of this antibody... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 13 of 13 results Showing all 13 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Cell Context DNA Repair Homologous Recombination Reporter Cells Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase DR3000Custom Cell Based Screening Kit for (HR) Pathway This kit contains reagents necessary to create a complete HR reporter system in any animal cell line. It includes an HR-GFP reporter with a selectable marker and a DS DNA cleavage nuclease to initiate HR. Because GFP is a neutral gene reporter and not subject to selection, the HR process can easily be examined and assayed by assessing the %GFP or GFP intensity in a population of cells. The system is mobile in that it can be incorporated in any cell lineage or species to adapt to the investigators system of study. Read more Select Custom Screening 1, 25 Assays —... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 14 of 14 results Showing all 14 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Topo Related Drugs Gyrase & Topo IV Topo I Topo II Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG410310-Hydroxy Camptothecin10-Hydroxy Camptothecin has shown promising activity against a range of tumour types. This CPT derivative causes cell toxicity by stabilizing a ternary complex between the nuclear enzyme topoisomerase I (topo I) and double-stranded DNA, leading to single and double strand breaks. TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase I. Read more$130. 00 Max: Min: 1 Step: 1 Add to CartTG41049-Amino Camptothecin 9-Amino-20-(R,S)-camptothecin (also known as 9-amino campthecin) is an analogue of camptothecin. Like other CPT congeners, it shows some promising activity against a range of tumor types. This compound causes cell toxicity by stabilizing a ternary complex between the nuclear enzyme topoisomerase I (topo I) and double-stranded DNA, leading to single and double... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 3 of 3 results Showing all 3 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products TPD2 Products Human TPD2 Human TPD2 Assay Kit TPD2 Substrate Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2003HHuman TDP-2 Tyrosyl-DNA phosphodiesterase-2 (Human TDP2) functions to remove trapped topoisomerase II/DNA complexes by processing 5′- blocking protein (topo II) at the site of the DNA break. In terms of physiological relevance, there appear to be multiple roles for TDP2, well beyond the repair of type II topoisomerase damage and subsequent DNA repair. Read more Select 50 ug — $520. 0025 ug — $420. 00 Max: Min: 1 Step: 1 Add to CartTG1005Human TDP-2 Assay KitTDP-2 is a relatively recently discovered repair protein. TDP2 (unlike TDP1) is specifically directed to act on phosphotyrosyl bonds that form when topoisomerase II is covalently trapped on the DNA helix. This Kit is designed to assay Human TDP-2 activity using a novel,... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 5 of 5 results Showing all 5 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products DNA Substrates Buffer Decatenated kDNA Marker kDNA Linear kDNA Marker Relaxed pHOT-1 Supercolied pHOT-1 Download CSV Sort by Sort by Name A - Z Sort by Name Z - A Sort by Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2013Kinetoplast DNA (kDNA) Kinetoplast DNA (kDNA) is the ideal substrate for topoisomerase II assays because it is specific for type II reaction mechanisms. Researchers can even assay for a type II enzyme in the presence of large excess of topoisomerase I. Thus, kDNA works well to quantify type II activity in crude cell extracts, which are frequently overloaded with topoisomerase I. kDNA works exceptionally well with human Top 2a and b as well as prokaryotic enzymes, such as DNA Gyrase or Topoisomerase IV. This substrate is packaged with our Topo II Assay Kit, Topo II Drug Screening Kit, and Gyrase Assay Kits. Read more Select 25 ug — $275. 0050 ug — $400. 00250 ug —... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTIST- Showing 1 – 15 of 16 results Showing all 16 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Topo Antibodies Antibody Kits Protein MW Markers Topoisomerase I Antibodies Topoisomerase II Immunoflourescence Kit Topoisomerase III Antibodies Topoisosomerase II Antibodies Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2011-3Human Topoisomerase II Alpha Molecular Weight MarkerThe marker set for topo II is used to unambiguously locate the position of the 170 kDa topo II in Western Blots. The human 170 kDa is present in SDS-PAGE loading buffer. Note that human topo II may break down spontaneously with prolonged storage or with repeated freezing and thawing cycles. TopoGEN, Inc. stipulates that the marker be 90% undegraded at the time of shipment. Read more$375. 00 Max: Min: 1 Step: 1 Add to CartTG2011-5Monoclonal Antibody to Human Topoiosomerase II Beta This mouse monoclonal antibody is directed specifically against purified Topo IIb. Because the two isoforms are very close in MW,... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 6 of 6 results Showing all 6 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Drug Screening Kits Gyrase Gyrase (Plasmid Based) Topo I Topo I Hi-Loading Inhibition Kit Topo II Topo II (kDNA Based) Topo IV Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2001GKITE. coli DNA Gyrase Drug Screening Kit (Plasmid Based) This kit is designed to screen for novel gyrase targeting drugs, either as interfacial poisons (or IFPs that induce cleavage of DNA) Catalytic inhibitory compounds (CICs that block gyrase action by any number of mechanisms). It is a straight forward gel assay kit that is easily adopted. This kit contains purified bacterial (E. coli) DNA Gyrase purified to homogeneity (>98% based on SDS-PAGE), as well as substrate relaxed DNA (plasmid pHOT1). Read more Select 100 Assays — $460. 00500 Assays — $985. 001000 Assays — $1,755. 002000 Assays — $2,855. 00 Max: Min: 1 Step: 1 Add... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 15 of 24 results Showing all 24 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Topo Kits DNA Unwinding Kit Gyrase & Relaxed DNA Assay Kit Gyrase Assay Kit ICE Assay Kit Kit Replenishments TopI-NuEx Kit TopII-NucEx Kit Topo I Assay Kit Topo II Assay Kit Download CSV Sort by Sort by Name A - Z Sort by Name Z - A Sort by Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG1015Human Topoisomerase I Assay KitHuman Topoisomerase I Assay Kit contains all the necessary reagents for routine detection of Topoisomerase I activity. The included DNA markers allow unequivocal detection of the enzyme. The assay is specific for topoisomerase I enzyme; (eukaryotic type II topoisomerases require MgCl2 and ATP). Read more Select 100 Assays — $320. 00250 Assays — $420. 00100 Assays + 100 Units Enzyme — $450. 00250 Assay + 250 Units Enzyme — $600. 00500 Assays + 500 Units Enzyme — $750. 00 Max: Min: 1 Step: 1 Add to CartTG1001Human Topoisomerase II Assay KitThis kit is designed to... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 2 of 2 results Showing all 2 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products DNA Gyrases E. coli DNA Gyrase S. aureus DNA Gyrase Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2000GE. Coli DNA Gyrase EnzymeTopoGEN’s purified E. coli DNA gyrase is widely used as a reliable, mechanistically-informative enzyme system for in vitro supercoiling assays, antibacterial lead screening, and mechanism-of-action classification. Investigators use gyrase assays both to identify compounds that trap cleavage complexes (interfacial poisons) versus those that block catalysis (catalytic inhibitors), enabling faster and more confident triage of antibacterial candidates. Beyond screening, gyrase assays have helped enable discovery of new bacterial control mechanisms, including toxin-driven modifications of type IIA topoisomerases, reinforcing gyrase as a central hub in bacterial viability and stress biology. Read more Select 100 Units — $370. 00500 Units — $700. 001000 Units — $1,100. 002000 Units — $1,800. 00 Max: Min: 1 Step: 1 Add... -ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS- Showing 1 – 4 of 4 results Showing all 4 results Showing the single result No results found All Categories Antibody Kits Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits Gyrase and Topo IV Homologous Recombination Reporter Cells Kit Replenishments Mobile Transient Assay DNA Repair Systems Non-Homologous End Joining Reporter Cells Protein MW Markers TDP1 Products Topo Antibodies Topo Enzymes Topo I Topo I Antibodies Topo II Topo II Antibodies Topo III Antibodies Topo Kits Topoisomerase Related Drugs TPD2 Products Topo Enzymes E. Coli Topo IV Human Topo I Human Topo IIA Mutant Human Topo I Download CSV Sort by Name A - Z Sort by Name A - Z Sort by Name Z - A Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase TG2000ECE. coli Topoisomerase IV EnzymeE. coli Topo IV is a type II topoisomerase that is encoded by two genes parC and parE in E. coli. It is essential for decatenation and chromosomal segregation in E. coli; thus, topo IV tends to prefer intermolecular strand passing (catenating and decatenating reactions) over relaxation reactions. It is overexpressed and purified for use. Read more Select 250 Units — $400. 00500 Units — $650. 001000 Units — $985. 00 Max: Min: 1 Step: 1 Add to CartTG2005HRCHuman Topoisomerase I EnzymeHigh purity, catalytically active Top1 Enzyme overexpressed in the baculovirus system and purified to single band homogeneity. These preparations are cheaper than native topo I made from... My AcoountLogin -Support Tools- QUICK LINKS TO PRODUCT SUPPORT PROTOCOLS VIEW FAQs VIEW SERVICES QUOTE FORM This is an example page. It's different from a blog post because it will stay in one place and will show up in your site navigation (in most themes). Most people start with an About page that introduces them to potential site visitors. It might say something like this: Hi there! I'm a bike messenger by day, aspiring actor by night, and this is my website. I live in Los Angeles, have a great dog named Jack, and I like piña coladas. (And gettin' caught in the rain. ) ... or something like this: The XYZ Doohickey Company was founded in 1971, and has been providing quality doohickeys to the public ever since. Located in Gotham City, XYZ employs over 2,000 people and does all kinds of awesome things for the Gotham community. As a new WordPress user, you should go to your dashboard to delete this page and create new pages for your content. Have fun! IN VITRO SCREENING FOR TOPO TARGETING DRUGS We can tractably identify novel Topo poisons and catalytic inhibitors. Got a grant proposal due? We offer rapid turn around services! All data controlled, documented and certified as publication quality. Your lab may lack expertise and experience, let us help stretch your grant dollars! We can report back in 2-4 business days with a full report. We offer services for Top1, Top2A DNA Gyrase and TopIV. Learn More KEY IMMUNO REAGENT RESOURCE FOR YOUR TOPOISOMERASE R&D We are a comprehensive source for all eukaryotic topo antibodies. Fully validated from in vitro and in situ (Cell context use) Learn More CELL CONTEXT SCREENS FOR DNA REPAIR (NEW! ) Screens that identify novel homology repair or non homology repair druggable targets. Modular screens can be placed inside your cell of choice. Identify new drugs or endogenous protein factors that Regulate/Target DNA repair. Relies on I-SCE1 specific DS breaks to initiate a specific repair pathway. Learn More Interrogate HR and NHEJ Repair We now offer plasmid based, mobile repair reporter sets. Learn More PRODUCTS All Products, Such as DNA substrates, are carefully validated for use with topoisomerases and gyrases. TopoGEN's enymes are high purity and consistent. Learn More KITS Our Kits are optimized for ease of use. They are well controlled with clear documentation. WE OFFER ON-LINE SUPPORT! Learn More SERVICES Our Contract R&D services include cell context and in vitro HTS for rapidly finding Learn More and optimizing new topo or gyrase drugs. We save... Watch Video TopoGEN is a renowned research diagnostics company that specializes in delivering innovative solutions to researchers focused on topoisomerase enzymes. Our expertise lies in supporting mechanism-based drug discovery and development, providing indispensable resources for academic and industrial researchers alike. WE ARE DEDICATED TO SUPPORTING YOU TopoGEN is a research diagnostics company that provides innovative products and services for researchers working with DNA Topoisomerases as well as DNA repair. Scientists engaged in mechanism-based anticancer, anti-viral and antibacterial drug discovery will find our products particularly useful in R&D. Our Drug Screening Kits are available to unambiguously identify topoisomerase targeting molecules for use in cancer chemotherapy and antibacterial applications. The company also sells assay kits that detect and quantify both prokaryotic (DNA Gyrase, Topoisomerase IV) and eukaryotic topoisomerases (Topoisomerase I, IIa, IIb, III). We also offer a complete line of DNA substrates and DNA cleavage targets, topoisomerase inhibitors, topoisomerase antibodies, and kit replenishment reagents. A related series of products on DNA repair are also a key part of our offering. Topoisomerase drugs often induce genomic DNA damage, thereby killing the tumor cell. When combined with agents that mitigate or inhibit DNA repair, the panoply of Topo Drugs and their tumor cell killing, may be significantly elevated. For this reason, TopoGEN scientists have also developed highly specific cell lines that allow researchers to interrogate endogenous DNA repair pathways (Homologous Recombination Repair or HR and Non-Homologous End Joining or NHEJ) all within the context of the live cell. Drugs that target HR and NHEJ... Contact number (614) - 451-5810 MAIN (614)-559-3932 FAX Mail address SUPPORT@TOPOGEN. COM INFO@TOPOGEN. COM SALES@TOPOGEN. COM Headquarters HEADQUARTERS TOPOGEN, INC. 27960 COUNTY RD. 319 UNIT B BUENA VISTA, CO 81211, USA FIRST NAME *LAST NAME *EMAIL ADDRESS *PHONE NUMBER *SUBJECT *Academic PartnershipDistribution PartnersGeneral InquiryGrantsInternshipsNewsProductsServicesShippingSupportVentures & AlliancesMESSAGE0 / 180 SEND MESSAGEEdit form OUR RESEARCH Reputable and dependable laboratory research Contract R&D Consequat mauris nunc congue nisi vitae suscipit tellus. Quis eleifend quam adipiscing vitae proin sagittis View more Virtual consultation Consequat mauris nunc congue nisi vitae suscipit tellus. Quis eleifend quam adipiscing vitae proin sagittis View more OUR PRODUCTION The workflow in our laboratory operations. 1 1 Formula Organic 2 2 Development Organic 3 3 Manufacture Organic 4 4 Samples Organic Are you ready to book an appointment now! Error: Contact form not found. Clients Testimonials Some of our clients reviews Liber iriure vix cu, fugit dicat no qui, posse detraxit has cu. Ex sint impedit vim,autem justo oportere no vel. Cu esse tacimates moderatius sed. Liber iriure vix cu, fugit dicat no qui, posse detraxit has cu. Jon Haris Web Developer Liber iriure vix cu, fugit dicat no qui, posse detraxit has cu. Ex sint impedit vim,autem justo oportere no vel. Cu esse tacimates moderatius sed. Liber iriure vix cu, fugit dicat no qui, posse detraxit has cu. Jon Haris Web Developer Liber iriure vix cu, fugit dicat no qui, posse detraxit has cu. Ex sint impedit vim,autem justo oportere no vel. Cu esse tacimates moderatius sed. Liber iriure vix cu, fugit dicat no qui, posse detraxit has cu. Jon Haris Web Developer Liber iriure vix cu, fugit dicat no qui, posse detraxit has cu. Ex sint impedit vim,autem justo oportere no vel. Cu esse tacimates moderatius sed. Liber iriure vix cu, fugit dicat no qui, posse detraxit has cu. Jon... OUR WORK Medical, medicine and health science case studies OUR TEAM Lets meet our professional team of scientists PRODUCTS + SERVICES + YEARS OF EXPERTISE TopoGEN SOLUTIONS Did you know that when you purchase our products, we offer free personalized support and consulting on use, application and data interpretation? Send us your data! WE CAN HELP! When you become our customer, we become your partner in research. We realize that sometimes you know what you are looking to accomplish but unsure of which products are order... . we can help. More to it, we will review your project and offer valuable and free consulting input from our years of experience. There might be something you are working on that happens to be research we are doing and collaborations like this happen often. Feel free to contact us for further information about how we can assist your topoisomerase research endeavors. ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTSCOMPOUND SCREENING QUOTE FORMWhy use our services? Find More TopoGEN scientists are the experts in efficiently screening compounds that impact topoisomerases and DNA gyrases. We can perform assays in vitro (using our purified enzymes and substrates) or in vivo (assay cells for Topo I or Topo Il poisons in our cell culture or assay your extracts) in order to identify new anti-cancer drugs, anti-infective agents, or to determine mechanism of action of your compounds. We can also measure topoisomerase levels or DNA-protein complexes from your cellular extracts. If you don't see what exactly what you are looking for, just send us a note and our scientists will talk to... WE ARE HONORED VENTURES & ALLIANCES Topogen has established joint collaborative ventures with other biotechnology companies. these relationships create excellent synergy and promote new product ideas and business activity. topogen uses a funding model to advance the goals of the joint venture. specifically, the company sponsors research based on validated and published science from other university faculty, other companies or collaborative partners. Learn more about our funding model 01 NANOLY BIOSCIENCES We are working with another start up located at Anschutz in Denver, CO on using their patented NanoShield technology to solve cold chain problems in the Biotech industry (labile vaccine storage and delivery, drug, biological storage issues). This work has been NIH funded and is ongoing. 02 PanoMatrix We have IP on a novel Nanocellulose that binds pathogens and promotes wound healing. This product is from a tree in the Amazon basin (Tagua) that has unique applications in beauty and skin care. 03 KARNALI, LTD. We have patented, in collaboration with Karnali, a copper-based anti-infective outer shoe sole for use in clinical medicine, food industry and the military and first responders. We have demonstrated that the product will mitigate spread of pathogens, including pandemic related viruses and can offer protection (in an ongoing basis) against disease spread. 04 CBX GENOMICS We an ongoing collaboration with a company developing novel cannabinoid compounds for use in cancer therapy. Screening for Topoisomerase Inhibitors and/or Poisions. Anticancer Screening for agents that target Human Topoisomerases: How we can advance your R&D. TopoGEN offers powerful and tractable services to identify Topoisomerase-targeting drugs In Vitro. Typically, Topoisomerase drugs by two distinct mechanisms: 1. Catalytc Inhibitory Compounds (Or CICS) 2. Interfacial Poisons (Or IFPS) These drugs block or restrict catalytic activity of the enzyme. Typically, CICs will act at steps 1 or 2 in the overall reaction sequence (see Fig. 1). By preventing the non-covalent (electrostatic or ionic bridge) complexes which are necessary to proceed to the cleavage complex (step 3), the reaction is effectively blocked. There are a number of Top2 CICs (ICRF-187) and many fewer Top1 CICs. Note that CICs can be highly non-specific since even elevated NaCl can even mimic a CIC. In other cases, strong DNA intercalators may interfere with the catalytic reaction sequence. Many in the field simply view a CIC as any agent that can interfere with the ability of a poison (like CPT and topo 1) to form cleavage complexes (ie, can ‘reverse or block’ the action of an IFP). This sort of dual drug testing approach can be complicated and we at TopoGEN have the view that it is better to directly test CICs in the absence of other drugs. We offer this as a service. These agents are technically poisons because they trap the re-ligation step in the sequence (or ‘poison’ the reaction sequence). Consequently, the enzyme becomes covalently trapped on the DNA target sequence... Cell Context Topo Screens (ICE Assays) TopoGEN offers powerful and tractable services to quantify the ability of your front line anticancer drug to specifically target endogenous topoisomerase action in cells. Lets face it, sometimes you get misled. Many promising lead compounds that appear to act on topo I or II with purified extracts or enzyme, never see the light of day; often because they fail to enter the nucleus/cell, become degraded or interconverted and simply do not hit the target topo for any number of reasons. This is the sort of information you need up front and early on. Rapid decision making is extremely critical. Wouldn’t it make sense to find out if the target (topo) is being hit as an active, endogenous enzyme? Topo enzymes are unusual DNA binding proteins in that they act by making transitory cleavage (or cleavable) complexes with the helix. IFP type drugs (Camptothecin, Etoposide) stabilize such complexes and pin the topo down on the template permanently. These DNA/topo complexes are said to be ‘covalent’ since the active site tyrosine hooks up to one or both DNA strands irreversibly leading to a highly stabilized complex that survives harsh treatments like SDS, elevated salt concentration or strong protein denaturants. This makes it possible to quantify such a complex using either a CsCl step gradient or our newer kit that avoids the density gradient step (TG1020- kits). The latter Kit is a series with different antibodies to interrogate different topoisomerases. Both Kits are based on the same... Bio-Correlations in Clinical Trials Bio-Correlations in Clinical Trials: TopoGEN offers powerful and tractable services to assist. New topo targeting compounds are constantly coming and going. Clinical trials in disease specific applications are active globally. TopoGEN can help with validation, target metrics and lead optimization by providing a framework for predictive response. Here are some of our services. Western Blotting Enzymes Assays We can accept cell pellets or tumor samples to quantify total cellular amounts of topoI, topoII, topoII or topoIII. We can make the extracts or we can perform the extractions. This approach offers a way to predict response and determine which patient population may or may not show clinical improvement. To complement total polypeptide levels from Westerns, we can extract enzymatically active topoI or II to quantify the activity of tumor associated protein. Topoisomerases are subject to post-translational effectors, and it is possible to have high or low total topo polypeptide levels that do not match activity. As above, we can make the salt extracts with your pellets or we can instruct your staff on the processing. In Vivo Link Kit (ICE Assays). This method can measure the endogenous action of topo in the tumor cell. The method is described (TG1021) and on a YouTube Video . The method is highly relevant clinically since it predicts the action of drug targeting in a cellular (chromatin) context. We direct the client on how to make the lysates and provide all required reagents. These extracts are then sent to use to... Western Blotting Services: Topo I,IIα,IIβ Protein Levels TopoGEN can quantify topoisomerase I, IIa, IIb and III levels in your extracts using Western Blotting and utilize our immune-reagents for cell distribution or localization experiments. We can also provide precise directions on making nuclear extracts and we will quantify topo levels by high resolution Western Blotting. The data will be publication quality with markers and precise quantitation. Testing 'Band Depletions' In this analysis we determine how well endogenous topo I or II is trapped onto genomic DNA. This is complementary to the In Vivo Link Kit. When cells are exposed to topo poisons, a fraction of the free enzyme becomes entrapped with high MW genomic DNA and cannot be extracted. This is reflected as a loss of band intensity of the nuclear extract, probed by Western blotting. Testing Levels of topo for biomarker or mechanistic studies with all human topo-enzymes. Immunofluorescent Cyto-localization experiments of topoisomerases. Immunoprecipitation with topoisomerases can be used to detect, quantify and recover either topoisomerases or Topo/DNA complexes. All of the above can be carried out using our Screening Services: Independent Validation, Expediency, Value, Publication ready. Our Screening Services: Independent Validation, Expediency, Value At TopoGEN, we developed, trademarked and patented many of the technologies associated with drug effects on DNA. We are leading experts at drug testing and assessment of drug action from a mechanistic standpoint. When you engage our services, we will describe and lay out a logical/rational approach that is rich in content and strongly mechanistic. We... Topoisomerase activity levels using customer extracts TopoGEN can quantify total topoisomerase I, II activity levels in your specific model cell line. We can provide precise directions on making nuclear extracts and we will quantify topo levels using biochemical assays (relaxation, decatenation or even Westerns for total topo protein levels). The data will be publication quality with markers and precise quantitation. This is very useful in a wide variety of applications. Typically, the customer is instructed on a defined protocol to make the extract and submits the samples for testing. We carry out titrations, quantify band intensities and analyze the data. Our Screening Services: Independent Validation, Expediency, Value At TopoGEN, we developed, trademarked and patented many of the technologies associated with drug effects on DNA. We are leading experts at drug testing and assessment of drug action from a mechanistic standpoint. When you engage our services, we will describe and lay out a logical/rational approach that is rich in content and strongly mechanistic. We offer independent consultants who can validate our findings. Our services offer expediency and value as well. We can significantly accelerate the pace of your research, produce publication quality data and you will own the intellectual property that comes with our studies. We routinely enter into confidentiality agreements on projects, so your results are protected. Our in-house testing program is flexible and efficient. The following are important points associated with our services: All Postitive & Negative Controls We demonstrate internally that all testing platforms are perfectly functional. As... Topo/DNA Complexes for Genomic Sequencing Studies Genomic Topoisomerase Studies: TopoGEN offers powerful and tractable services to assist you. Topoisomerases are unique DNA binding proteins. They engage the helix in a series of transient breaking-resealing reactions to allow topological adjustments that arise from DNA templating. What is unusual is that these enzymes engage DNA in a short-lived covalent mode. Specifically, the active site tyrosine for both type I and II enzymes, forms a phospho-tyrosyl link that is a covalent bond. The transient nature of this complex evolved to ensure that these enzymes do not permanently damage the genome; thus, a tight coupling between the cleavage/relegation ensures that DNA discontinuities never accumulate. Interfacial Poisons (IFP) kill tumor cells by stabilizing the discontinuity and trapping the phospho-tyrosyl link in a covalent bond to the sugar phosphate back bone of the helix. For detailed genomic studies, it would be useful to deep sequence all sites of action under the influence of a given IFP (for example VP16 for Topo II). These stable complexes can be analyzed by modern deep sequencing technology. Coupled with a clinical trial or for mechanistic consideration, this is a powerful approach. Customers need only follow the instructions in the In Vivo Link (ICE) kit and using our unique reagents, recover by IP the enriched topo/DNA complexes specific to a type I, IIα, IIβ cleavage event. We can help as well so please enquire about the details of our services. From this work flow additional analyses are possible: Testing 'Band Depletions'... Screening for new antibiotics that target DNA & Gyrase & Topoisomerase IV TopoGEN offers powerful and tractable services to identify Gyrase and Topoisomerase IV targeting antibiotics. These drugs can be subdivided into two large groups. 1. Catalytc Inhibitory Compounds (Or CICS) 2. Interfacial Poisons (Or IFPS) These drugs block or restrict catalytic activity of the enzyme. Typically, CICs will act at steps 1 or 2 in the overall reaction sequence. By preventing the non-covalent (electrostatic or ionic bridge) complexes which are necessary to proceed to the cleavage complex (step 3), the reaction is effectively blocked. This mechanism is not very common and may not be terribly effective in the prokaryotic domain. Note that CICs can be highly non-specific since even elevated NaCl can be a CIC. In other cases, strong DNA intercalators may interfere with the catalytic reaction sequence. These agents are technically poisons because they inhibit the re-ligation step in the sequence (‘poison’ the reaction sequence). Consequently, the enzyme becomes covalently trapped on the DNA target sequence and concurrently DNA cleavage is stabilized (single strand nick with topo I and double strand DNA break for topo II). Mechanistically, it appears that IFPs intervene stereochemically in the cleavage complex, forming what is called a ‘ternary complex’ (topo+drug+DNA) wherein the IFP drug induces a mis-alignment of the cleavage intermediate making it unable to re-ligate. When testing IFPs (see Step 3, Fig. 1) it is vital that you perform a proteinase K digestion step, otherwise the cleavage products will shift in the... FREQUENTLY ASKED QUESTIONS Why does the activity of the enzyme vary from lot to lot? Any topo preparation that passes our QC tests, has at least 2 units/ul based on decatenation assays with kDNA. Often we find that the activity is significantly greater (for example 4, 8 or 16 units/ul); however, since the enymes are unstable to dilution, we prefer to maintain concentrated stock enzyme and still sell it to the customer labeled conservatively. This is a good deal for the end user of course. On the other hand, we sometimes find that customers are confused by this since the activity seems to vary from lot to lot. One lot may be very very active (16 units/ul) and the next lot may be only 4 units/ul. If you need to standardize the assay from one lot the next, we suggest that you titer the activity in your own lab using your own assays. Another reason we sell the enzyme “hotter” than expected is that many researchers use them in cleavage assays which require higher levels of activity (compared to catalytic assays–see questions and discussion below). What is the best way to store Topo Enzymes after we receive them? Topo II is best kept at -70, while topo I and gyrase can be stored at -20 C. We suggest that you aliquot the enzyme into smaller fractions and try to minimize freeze thaw cycles. Both topo I and II may retain activity when stored in wet ice (0-4 C) for a... ALL OF OUR PRODUCTS ARE VALIDATED & CERTIFIED BY TOPOGEN SCIENTISTS COMPOUND SCREENING QUOTE REQUEST TopoGEN scientists are the experts in efficiently screening compounds that impact topoisomerases and DNA gyrases. We can perform assays in vitro (using our purified enzymes and substrates) or in vivo (assay cells for Topo I or Topo II poisons in our cell culture or assay your extracts) in order to identify new anti-cancer drugs, anti-infective agents, or to determine mechanism of action of your compounds. We can also measure topoisomerase levels or DNA-protein complexes from your cellular extracts. If you don’t see what exactly what you are looking for, just send us a note and our scientists will talk you about how we can help and then prepare a quote for you. In most cases we can perform a study faster and at lower cost than your in-house work because we already have all the reagents and controls and are fully set up to run your assays. How many compounds do you have to be tested? *Wht stock molar concentration can you provide? *The maximum volume I can supply is *What solvent is the compound dissolved in? *How soon do you need the results (from now)? *SERVICE TYPE(please select all that apply)In Vitro Drug Screening For:Topo I Catalytic InhibitionTopo II Catalytic InhibitionE. coli DNA Gyrase Catalytic InhibitionE. coli Topo IV Catalytic InhibitionS. aureus DNA Gyrase Catalytic InhibitionS. aureus Topo IV Catalytic InhibitionIn Vitro Drug Screening For:Topo I PoisionsTopo II PoisionsE. coli DNA Gyrase PoisonsE. coli... TECHNICAL LITERATURE IN VIVO LINK KIT Click In Vivo Link Kit Topo I-II to download PDFIn Vivo Link Kit for Analysis of Topo I or II Covalent Complex Formation Inside Cells (see ICE Assay Kit TG1020)Kit DescriptionTopoGEN has extensive experience with assays for topoisomerase inhibition in vivo. These experiments allow the investigator to ascertain whether a novel agent is active against endogenous topo in a chromosomal setting in nuclei. An important benefit to this analysis is that one can use any tumor cell or tissue in order to establish clinical efficacy of a test drug against a specific tumor cell line. We use essentially the same basic approach for Topo I as for Topo II. The methods are based upon physically separating the topo/DNA adducts from free DNA and using antibodies to measure bound topo I or II. In this analysis, tissue culture cells are treated with a test compound along with negative controls (no drug) and positive controls (with known inhibitors). The cells are drug treated and rapidly lysed with Sarkosyl which traps some fraction of the endogenous topo on DNA in a covalent cleavage complex. Following detergent lysis, the lysate is diluted to fully dissociate non-covalent DNA/protein complexes. Covalent topo/DNA complexes are resolved on a step CsCl gradient (ionic DNA/protein interactions are also prevented by 5 M CsCl). The gradient resolves DNA, chromatin aggregates, and protein, respectively. Gradients are centrifuged overnight and fractionated. The amount of topo coincident with the DNA peak is a measure of covalent DNA/topo... 13 June 2024 Accelerate Your R&D Output with the New IQ Screen Contract Screening Services Exciting News from TopoGEN, Inc. We are thrilled to announce the launch... Read More 11 June 2024 CELL CONTEXT DNA REPAIR KITS NOW AVAILABLE Cell Context DNA Repair Kits Are you working on DNA-damage and repair? Would you be interested in a... Read More 11 June 2024 Contract R&D to Identify Drugs that Target Human Topo I, Topo II, Bacterial Topo IV and DNA Gyrase Experience. Rapid Turn-Around. Publication Quality. TopoGEN has >20 yrs. experience in the area as... Read More 11 June 2024 SBIR-Funded Alliance to Conquer the Cold-Chain SBIR-Funded Alliance to Conquer the Cold-Chain Topoisomerase I July 20, 2018 TopoGEN was featured in... Read More Meelad M. Dawlaty, Liviu Malureanu, Karthik B. Jeganathan, Esther Kao, Claudio Sustmann, Samuel Tahk, Ke Shua, Rudolf Grosschedl, and Jan M. van Deursen Resolution of Sister Centromeres Requires RanBP2-Mediated SUMOylation of Topoisomerase IIa Cell 2008 133: 103-115. Darren J. Burgess, Jason Doles, Lars Zender, Wen Xue, Beicong Ma, W. Richard McCombie, Gregory J. Hannon, Scott W. Lowe, and Michael T. Hemann Topoisomerase Levels Determine Chemotherapy Response In Vitro and In Vivo PNAS communicated by Michael H. Wigler, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, April 2008. Cai Bowen, August Stuart, Jeong-Ho Ju, Jenny Tuan, Josip Blonder, Thomas P. Conrads, Timothy D. Veenstra, and Edward P. Gelmann NKX3. 1 Homeodomain Protein Binds to Topoisomerase I and Enhances Its Activity Cancer Res. 2007 67: 455-464. Anthony Maxwell, Nicolas P. Burton and Natasha O’Hagan High-throughput Assays for DNA Gyrase and other Topoisomerases Nucleic Acids Research 2006 34: No. 15 e104. Alexandre Santos, Loreley Calvet, Marie-Josee Terrier-Lacombe, Annette Larsen, Jean Bénard, Corinne Pondarré, Geneviève Aubert, Jackie Morizet, François Lavelle, and Gilles Vassal In Vivo Treatment with CPT-11 Leads to Differentiation of Neuroblastoma Xenografts and Topoisomerase I Alterations Cancer Res. 2004 64: 3223-3229. Hanlin Gao, Edith F. Yamasaki, Kenneth K. Chan, Linus L. Shen, and Robert M. Snapka Chloroquinoxaline Sulfonamide (NSC 339004) Is a Topoisomerase II/ß Poison Cancer Res. 2000 60: 5937-5940. WuCarrie Walowsky, David J. Fitzhugh, Irene B. Castaño, Justina Y. Ju, Nikki A. Levin, and Michael F. Christman The Topoisomerase-related Function Gene TRF4 Affects Cellular Sensitivity to the Antitumor Agent Camptothecin J.... JOINING THE TOPOGEN TEAM Here at TopoGEN we foster a ongoing learning environment to train students (from high school to university level) who wish to learn hands-on the technical and intellectual aspects of biotech. We welcome applications from highly motivated students interested in a future career with the Company or help with making career decisions in our field. In addition to hands-on training, interns and trainees will learn the science behind their project. Contact us if you are interested in either working as an intern for the summer or academic year or in a more lengthy relationship of employment. You won’t be disappointed! ! . For those seeking a long term employment track with TopoGEN, we encourage you to apply. We pride ourselves on our ability to teach and train incoming technical staff (the Company was founded by former academics (university faculty, specifically) and we are seasoned educators). Life in the company is characterized by ongoing learning (seminars, paper presentations) and laboratory work. We offer high flexible hours and make efforts to create independent researchers and critical thinking about science. Let us know if you have an interest in a career path with TopoGEN. APPLY HERE! You agree to be bound by the Terms and Conditions (“Terms and Conditions”) contained herein by using this Website. Accordingly, you should read them with care. If you do not agree to these Terms and Conditions, do not use this Website or make any purchase from it. The Terms and Conditions contained herein govern your use of, and any purchase from, the TopoGEN Website. TopoGEN reserves the right to change or modify any of these Terms and Conditions or any policy or guideline of this Website in its sole discretion by posting such changes or modifications to this Website. Changes and modifications will be effective immediately upon posting to this Website. Your continued use of this Website following the posting of such changes or modifications constitutes acceptance of them. Therefore, you should frequently review these Terms and Conditions and any other applicable policies to understand the Terms and Conditions that apply to your use of this Website. If you do not want to be bound by the amended Terms and Conditions, stop using this Website. Product Availability and Pricing Products displayed on this Website are not always available for immediate shipping. While we make every effort to keep the Website current, available inventory is subject to change without prior notice. If you need a product shipped within forty-eight hours, we recommend that you contact the Website Customer Service Department at info@topogen. com which should be able to tell you whether or not the product can be shipped in that time... WHY CHOOSE US WE ARE DEDICATED TO SUPPORTING YOU TOPOGEN products are available throughout the world via our network of international distributors. Please contact the local distributor for availability, pricing and product support. If your country is not listed, please contact us at our North American office. Thank You! - TOPOGEN’S - PARTNERS In situ Screen (cell context) Screening TopoGEN offers powerful and tractable services to quantify the ability of your front line anticancer drug to specifically target endogenous topoisomerase action in cells. Lets face it, sometimes you get misled. Many promising lead compounds that appear to act on topo I or II with purified extracts or enzyme, never see the light of day; often because they fail to enter the nucleus/cell, become degraded or interconverted and simply do not hit the target topo for any number of reasons. This is the sort of information you need up front and early on. Rapid decision making is extremely critical. Wouldn’t it make sense to find out if the target (topo) is being hit as an active, endogenous enzyme? Topo enzymes are unusual DNA binding proteins in that they act by making transitory cleavage (or cleavable) complexes with the helix. IFP type drugs (Camptothecin, Etoposide) stabilize such complexes and pin the topo down on the template permanently. These DNA/topo complexes are said to be ‘covalent’ since the active site tyrosine hooks up to one or both DNA strands irreversibly leading to a highly stabilized complex that survives harsh treatments like SDS, elevated salt concentration or strong protein denaturants. This makes it possible to quantify such a complex using either a CsCl step gradient or our newer kit that avoids the density gradient step (TG1020- kits). The latter Kit is a series with different antibodies to interrogate different topoisomerases. Both Kits are based on the same... Topo/DNA Complexes for Genomic Sequencing Studies Genomic Topoisomerase Studies: TopoGEN offers powerful and tractable services to assist you. Topoisomerases are unique DNA binding proteins. They engage the helix in a series of transient breaking-resealing reactions to allow topological adjustments that arise from DNA templating. What is unusual is that these enzymes engage DNA in a short-lived covalent mode. Specifically, the active site tyrosine for both type I and II enzymes, forms a phospho-tyrosyl link that is a covalent bond. The transient nature of this complex evolved to ensure that these enzymes do not permanently damage the genome; thus, a tight coupling between the cleavage/relegation ensures that DNA discontinuities never accumulate. Interfacial Poisons (IFP) kill tumor cells by stabilizing the discontinuity and trapping the phospho-tyrosyl link in a covalent bond to the sugar phosphate back bone of the helix. For detailed genomic studies, it would be useful to deep sequence all sites of action under the influence of a given IFP (for example VP16 for Topo II). These stable complexes can be analyzed by modern deep sequencing technology. Coupled with a clinical trial or for mechanistic consideration, this is a powerful approach. Customers need only follow the instructions in the In Vivo Link (ICE) kit and using our unique reagents, recover by IP the enriched topo/DNA complexes specific to a type I, IIα, IIβ cleavage event. We can help as well so please enquire about the details of our services. From this work flow additional analyses are possible: Testing 'Band Depletions'... You may be interested in... Your cart is currently empty! New in store https://topogen. com/wp-content/uploads/2021/08/Topogen_HD-720p. mp4 - ACCELERATE YOUR RESEARCH PRODUCTIVITY WITH OUR - CUSTOM SCREENING SERVICES AND CONTRACT R&D TopoGEN offers turn-key, custom screening services to screen for new Topo Drugs that target Human Topo I, Topo II, Topo IV and DNA Gyrase. As an Experienced CRO, the advantages are numerous! Our group has >30 years experience as a Contract Research Organization. We guarantee clear, cosmetic data, unambiguous interpretations, and that you will receive publication quality results. Since we are seasoned veterans in the arena of in vitro testing, we can help you develop a tractable strategy for analysis of drug mechanisms in the context of the tumor cell. We can evaluate potential genotoxicity independently from topo effects without extra charge. All our topo enzymes are homogeneously pure. We do not screen using extracts. Controls with specific drugs (e. g. etoposide vs. Top2a) guarantee specificity in all assays and validate even negative results with unknowns. Additionally, we produce quality topoisomerases & related assay and drug screening kits as technology transfer platforms from our lab to yours. When you become our customer, we become your partner in research. We review your data and offer valuable input. Feel free to contact us for further information about how we can assist your topoisomerase research endeavors. Click here to fill out our custom quote form HUMAN TOPO SCREENING IN VITRO Do have a drug that might target human topoisomerase? We can help! Let us design a tractable screen to validate your novel small molecule or natural... all of OUR PRODUCTS are validated & certified with Topo-enzymes For Cancer Research & Drug DiscoveryWooCommerce Product Table NoticeNo product table settings were found for this id. Please try clicking the "Save settings" button at the bottom of the table editor page to save your table settings. If you have already done this and the issue still persists, the cause may be incompatibility with another script on your site. In that case you should contact the plugin developer here for prompt support. OUR SERVICESWhy Choose UsWhen you become our customer, we become your partner in research. We review your data and offer valuable input. Feel free to contact us for further information about how we can assist your topoisomerase research endeavors. all of OUR PRODUCTS are validated & certified with Topo-enzymes For Cancer Research & Drug DiscoveryWooCommerce Product Table NoticeNo product table settings were found for this id. Please try clicking the "Save settings" button at the bottom of the table editor page to save your table settings. If you have already done this and the issue still persists, the cause may be incompatibility with another script on your site. In that case you should contact the plugin developer here for prompt support. OUR SERVICESWhy Choose UsWhen you become our customer, we become your partner in research. We review your data and offer valuable input. Feel free to contact us for further information about how we can assist your topoisomerase research endeavors. all of OUR PRODUCTS are validated & certified with Topo-enzymes For Cancer Research & Drug DiscoveryWooCommerce Product Table NoticeNo product table settings were found for this id. Please try clicking the "Save settings" button at the bottom of the table editor page to save your table settings. If you have already done this and the issue still persists, the cause may be incompatibility with another script on your site. In that case you should contact the plugin developer here for prompt support. OUR SERVICESWhy Choose UsWhen you become our customer, we become your partner in research. We review your data and offer valuable input. Feel free to contact us for further information about how we can assist your topoisomerase research endeavors. our kits are well controlled, fully documented kits for topoisomerase projects & for interrogating dna repair pathway events kits For Cancer Research & Drug Discovery Showing 1 – 15 of 43 results Showing all 43 results Showing the single result No results found Category Cell Context DNA Repair Drug Screening Kits Kit Replenishments Topo Kits Download CSV Sort by Sort by Name A - Z Sort by Name Z - A Sort by Filters Sort results Reset Apply Product IDProduct InfoDescriptionPurchase DR3000-HRHeLa-SceHuman: HeLa Reporter Cell Line (Includes I-Sce1 Transfection) Select 25 Assays — $1,975. 0050 Assays — $2,245. 00125 Assays — $2,795. 00 Max: Min: 1 Step: 1 Add to CartDR3000-HRHeLaHuman: HeLa HR Reporter Cell line (Includes CRISPR-CAS Transfection) Select 25 Assays — $2,085. 0050 Assays — $2,355. 00125 Assays — $2,895. 00 Max: Min: 1 Step: 1 Add to CartDR3000-HRSH-SceHuman: Neuroblastoma HR Reporter Cell line (SH-SY5Y, Includes I-Sce1 Transfection) Select 25 Assays — $2,415. 0050 Assays — $2,685. 00125 Assays — $3,235. 00 Max: Min: 1 Step: 1 Add to CartDR3000-HR3T3-SceMouse: 3T3 HR Reporter Cell Line (Includes I-Sce1 Transfection) Select 25 Assays — $1,975. 0050 Assays — $2,245. 00125 Assays — $2,795. 00 Max: Min: 1 Step: 1 Add to CartDR3000-HRCN1. 4-SceMouse: Neuronal Lineage HR Reporter Cell line (Includes I-Sce1 Transfection) Select 25 Assays — $2,415. 0050 Assays — $2,685. 00125 Assays — $3,235. 00 Max: Min: 1 Step: 1 Add to CartDR3000Custom Cell Based Screening Kit for (HR) Pathway Select Custom Screening 1, 25 Assays — $2,415. 00Custom... all of OUR PRODUCTS are validated & certified by TopoGEN Scientists For Research & Drug Discovery Showing 1 – -1 of 87 results Showing all 87 results Showing the single result No results found Category Cell Context DNA Repair DNA Gyrases DNA Substrates Drug Screening Kits TDP1 Products Topo Antibodies Topo Enzymes Topo Kits Topoisomerase Related Drugs TPD2 Products Download CSV Sort by Sort by Name A - Z Sort by Name Z - A Sort by Filters Sort results Reset Apply Product IDProduct InfoDescription DR3000-HRHeLaHuman: HeLa HR Reporter Cell line (Includes CRISPR-CAS Transfection)DRT5050Non-Homologous End Joining (NHEJ) Repair Reporter Kit (Transient Assay-Based Kit) This is a plasmid transfection based reporter system designed to allow the customer to screen or examine any agent that affects the process of NHEJ DNA repair. It will work in most of all cell lines that can be transfected. The kit uses GFP as an in vivo readout for NHEJ and includes two Plasmids... Show more (+) This is a plasmid transfection based reporter system designed to allow the customer to screen or examine any agent that affects the process of NHEJ DNA repair. It will work in most of all cell lines that can be transfected. The kit uses GFP as an in vivo readout for NHEJ and includes two Plasmids that are validated as high quality, transfection-grade DNA. Show less (-) DR3050Homologous Recombination (HR) Repair Reporter Kit (Transient Assay-Based Kit) This is a custom cell-based reporter system designed to allow researchers to study homologous... ## Products - Product type: variable - Product categories: Cell Context DNA Repair, Mobile Transient Assay DNA Repair Systems - Product tags: DNA Repair, Homogolous Recombination, HR DNA Reporter, NHEJ DNA KIT, Plasmid DNA - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Mobile Transient Assay DNA Repair Systems This is a plasmid transfection based reporter system designed to allow the customer to screen or interrogate any agent (drug or protein) that targets total NHEJ in the context of a live cell. The reporter plasmid in this kit reports on total NHEJ processes, which encompasses both classic and alternate pathways. It will work in most of all cell lines that can be transfected. The kit uses GFP as an in vivo readout for NHEJ and includes two Plasmids that are validated as high quality, transfection-grade DNA (see Figures 1 & 2). NEW: we are now offering an affordable trial size (50ug each of 3 plasmids in the Kit) to allow you to test the power of our new cell-based kits. We offer academic and for-profit pricing, please contact us for a quote. - Product type: variable - Product categories: Topo Enzymes - Product tags: human topo1, top1, topo I, topo1, topoisomerase 1, topoisomerase I - Product shipping classes: Domestic Dry Ice - Product Topo Enzymes: Human Topo I High purity, catalytically active Top1 Enzyme overexpressed in the baculovirus system and purified to single band homogeneity. These preparations are cheaper than native topo I made from human tissue and offer excellent purity and high specific activity. - Product type: simple - Product categories: Topo I, Topoisomerase Related Drugs - Product tags: Topo 1 - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Topo I 10-Hydroxy Camptothecin has shown promising activity against a range of tumour types. This CPT derivative causes cell toxicity by stabilizing a ternary complex between the nuclear enzyme topoisomerase I (topo I) and double-stranded DNA, leading to single and double strand breaks. TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase I. - Product type: variable - Product categories: DNA Gyrases - Product tags: DNA gyrase, gyrase, sa dna gyrase, saureus dna gyrase - Product shipping classes: Domestic Dry Ice Highly purified Staph aureus DNA gyrase is a type II topoisomerase encoded by two genes GyrA and GyrB from staphylococcus aureus. DNA gyrase is an essential topoisomerase that supercoils DNA through a process of strand breakage/resealing and DNA wrapping. As a type II enzyme, gyrase is unique in its ability to negatively supercoil a relaxed plasmid DNA substrate. S. aureus DNA gyrase is also the target for quinolone-based antibacterial agents which act by subverting the enzyme into a DNA damaging agent. TopoGEN offers purified DNA gyrase from the gram positive bacterium, Staphylococcus aureus for use in all aspects of drug development and screening assays. The enzyme is very active in decatenating and supercoiling kinetoplast DNA (kDNA) but will also negatively supercoil relaxed plasmid DNA. The Staph aureus enzyme is a heterotetramer of GyrA2GyrB2 and is purified as His tagged subunits that are reassembled to make active enzyme. - Product type: variable - Product categories: DNA Gyrases - Product tags: DNA gyrase, e.coli, gyrase - Product shipping classes: Domestic Dry Ice - Product DNA Gyrases: E. coli DNA Gyrase TopoGEN’s purified E. coli DNA gyrase is widely used as a reliable, mechanistically-informative enzyme system for in vitro supercoiling assays, antibacterial lead screening, and mechanism-of-action classification. Investigators use gyrase assays both to identify compounds that trap cleavage complexes (interfacial poisons) versus those that block catalysis (catalytic inhibitors), enabling faster and more confident triage of antibacterial candidates. Beyond screening, gyrase assays have helped enable discovery of new bacterial control mechanisms, including toxin-driven modifications of type IIA topoisomerases, reinforcing gyrase as a central hub in bacterial viability and stress biology. - Product type: variable - Product categories: Antibody Kits, Topo Antibodies, Topo Kits - Product tags: human topo 2, immunofluorescence kit, topo 2 - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Antibody Kits TopoGEN has extensive experience with assays for topoisomerase inhibition in vivo. This analysis allows the investigator to ascertain whether a novel agent is active against endogenous Top2bin whole cells. An important benefit to this analysis is that one can use any tumor cell or tissue in order to establish clinical efficacy against a specific tumor cell line. We use essentially the same basic approach for Topo I, and Topo IIa,b. The kit is based upon ‘band shifting’ in a western blot using mono-specific antibody probes for Top2a (TG1024-A) or Top2b (TG1024-B. This kit can be used to unambiguously detect a Top2a, or Top2b-specific poisoning in the context of a live cell. It is specific for Top2 poisons and not catalytic inhibitors. In addition, the kit can be used to profile the sensitivity of any given cell line to VP16 or other established Topoisomerase poisons. - Product type: simple - Product categories: Antibody Kits, Topo Antibodies, Topo Kits - Product tags: human topo 2, Immunoprecipitation Kit, topo 2 - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Antibody Kits The immunoprecpitation (IP) kit contains the key reagents and protocol for immunoprecipitating Human Top2a. The method should work well with other cells besides humans. For example, mouse, rat and monkey cells will cross react with topoisomerase II antibody. The antibody is specific for p170 (topo II alpha) in human (HeLa) cells and although we presume it will behave similarly in other species with cross reactive topo II isozymes, this should be carefully evaluated. - Product type: variable - Product categories: Drug Screening Kits - Product tags: drug screening, kdna, topo 2 drug screening kit - Product shipping classes: Domestic Dry Ice - Product Drug Screening Kits: Topo II (kDNA Based) This kDNA based Topo II Drug Screening Kit is designed to identify agents that target type II topoisomerases acting as catalytic inhibitors, primarily; however, poisons can also be detected with this kit. - Product type: variable - Product categories: Topo Enzymes - Product tags: topoisomerases - Product shipping classes: Domestic Dry Ice - Product Topo Enzymes: E. Coli Topo IV E. coli Topo IV is a type II topoisomerase that is encoded by two genes parC and parE in E. coli. It is essential for decatenation and chromosomal segregation in E. coli; thus, topo IV tends to prefer intermolecular strand passing (catenating and decatenating reactions) over relaxation reactions. It is overexpressed and purified for use. - Product type: variable - Product categories: Cell Context DNA Repair, Mobile Transient Assay DNA Repair Systems - Product tags: DNA Repair, Homogolous Recombination, HR DNA Reporter, Plasmid DNA - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Mobile Transient Assay DNA Repair Systems HR DNA Repair Reporter Kit by Plasmid Transfection Assay designed to allow researchers to study Homologous Recombination (HR) in a cell line of their choosing. The kit uses GFP as an in vivo readout for the HR pathway and includes proper controls to set the system up in your own lab. NEW: we are now offering an affordable trial size (50ug each of 3 plasmids in the Kit) to allow you to test the power of our new cell-based kits. We offer academic and for-profit pricing, please contact us for a quote. - Product type: variable - Product categories: Cell Context DNA Repair, Non-Homologous End Joining Reporter Cells - Product tags: DNA Repair, NHEJ, Plasmid DNA - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Non-Homologous End Joining Reporter Cells Custom Cell Based Screening Kit for NHEJ contains reagents necessary to create a complete NHEJ reporter system in any animal cell line. It includes the NHEJ-GFP reporter with a selectable marker and a DS DNA cleavage nuclease to initiate DNA repair. - Product type: variable - Product categories: Cell Context DNA Repair, Homologous Recombination Reporter Cells - Product tags: DNA Repair, Homologous Recombination, HR DNA Reporter - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Homologous Recombination Reporter Cells This kit contains reagents necessary to create a complete HR reporter system in any animal cell line. It includes an HR-GFP reporter with a selectable marker and a DS DNA cleavage nuclease to initiate HR. Because GFP is a neutral gene reporter and not subject to selection, the HR process can easily be examined and assayed by assessing the %GFP or GFP intensity in a population of cells. The system is mobile in that it can be incorporated in any cell lineage or species to adapt to the investigators system of study. - Product type: variable - Product categories: Cell Context DNA Repair - Product tags: DNA Repair, NHEJ - Product shipping classes: Domestic Dry Ice TopoGEN scientists have created a novel, cell based kit to follow NHEJ by simply assaying for the presence of GFP positive cells. The CN1. 4 cell line is a clone derived from mouse embryonic day 13 neuronal cultures. The line was transformed using the temperature-sensitive SV-40 Large T-antigen The kit uses GFP as an in situ readout for NHEJ activity in a cell context. - Product type: variable - Product categories: Cell Context DNA Repair, Non-Homologous End Joining Reporter Cells - Product tags: DNA Repair, NHEJ - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Non-Homologous End Joining Reporter Cells This is a Mouse 3T3 cell-based reporter kit designed to allow the customer to screen or identify agents (drugs, natural products, small molecules, synthetics, miRNAs, and other genes) that affect or impact NHEJ repair. The kit uses GFP as an in situ readout for NHEJ activity in a cell context. - Product type: variable - Product categories: Cell Context DNA Repair, Non-Homologous End Joining Reporter Cells - Product tags: DNA Repair, NHEJ - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Non-Homologous End Joining Reporter Cells This is a cell-based reporter kit that is hosted by a human neuroblastoma cell line (SH-SY5Y) that can grow continuously in vitro and will terminally differentiate. This provides the opportunity of analyzing NHEJ in growing or terminally differentiated cells in a neuronal lineage. - Product type: variable - Product categories: Cell Context DNA Repair, Non-Homologous End Joining Reporter Cells - Product tags: DNA Repair, NHEJ - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Non-Homologous End Joining Reporter Cells This is a HeLa cell-based reporter kit designed to allow the customer to screen or identify agents (drugs, natural products, small molecules, synthetics, miRNAs, and other genes) that affect or impact NHEJ repair. The kit uses GFP as an in situ readout for NHEJ activity in a cell context. - Product type: variable - Product categories: Cell Context DNA Repair, Homologous Recombination Reporter Cells - Product tags: DNA Repair, Homologous Recombination, HR DNA Reporter - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Homologous Recombination Reporter Cells This is the first HR reporter that has been engineered into a neuronally derived mouse cell line model. The CN1. 4 cell line is a clone derived from mouse embryonic day 13 neuronal cultures. The line was transformed using the temperature-sensitive SV-40 Large T-antigen. The cell line expresses numerous neuronal markers, including neurofilaments, glutamic acid decarboxylase 67, neuron-specific enolase, and the BG21 isoform of the myelin basic protein gene. - Product type: variable - Product categories: Cell Context DNA Repair, Homologous Recombination Reporter Cells - Product tags: DNA Repair, Homologous Recombination, HR DNA Reporter - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Homologous Recombination Reporter Cells This is a cell-based reporter kit designed to allow the customer to screen or identify agents (drugs, natural products, small molecules, synthetics, miRNAs, and genes) that affect or impact the process of HR DNA repair. The kit uses GFP as an in vivo readout for the HR pathway and a plasmid expression vector containing the mega-endonuclease I-Sce1. The HR reporter plasmid has been engineered into a mouse 3T3 cell line which is ideal for cell cycle analyses. - Product type: variable - Product categories: Cell Context DNA Repair, Homologous Recombination Reporter Cells - Product tags: DNA Repair, Homologous Recombination, HR DNA Reporter - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Homologous Recombination Reporter Cells DNA Repair pathways in animal cells can be divided into two main categories: HR and NHEJ. HR or homologous recombination is a minor pathway but very important in protecting cells from genotoxicity. HR needs a homologous sequence and is limited to S-phase. A specific reporter based assay for HR can be very beneficial for drug discovery projects, learning more about the process of DNA HR repair and establishing intersecting pathways and druggable pathway targets. This is the first HR reporter that has been engineered into a neuronally derived cell line. The SH-SY5Y cell line (SH) is a subclone of a bone marrow biopsy isolated from a 4 year old female patient with neuroblastoma, in 1973. The original SK-N-SH line was mixture of epithelial cells, as well as neuronal precursor cells. The current cell line is the 3rd subclone from the original line and displays mostly neuronal phenotypic markers. Cells are considered neuronal in phenotype due to the expression on known neuronal markers, such as dopamine b-hydroxlase activity, acetylcholinergic, glutamatergic, and adenosenergic activities, as well. In culture, the SH cell line is still a mixture of 2 different phenotypes. These cells can be forcibly differentiated by treatment with neurotrophic factors. Factors used to differentiate SH cells include retinoic acid (RA), brain-derived neurotrophic factor (BDNF), and tissue plasmin activator (TPA). Treatment with neurotrophic factors induce a more neuronal phenotype in SH cells, in culture, including dendrification, upregulation of production of neuronal markers (see above), and a transition from mitotic cells to post-mitotic,... - Product type: variable - Product categories: Cell Context DNA Repair, Homologous Recombination Reporter Cells - Product tags: DNA Repair, Homologous Recombination, HR DNA Reporter - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Homologous Recombination Reporter Cells This is a cell-based reporter kit designed to allow the customer to screen or identify agents (drugs, natural products, small molecules, synthetics, miRNAs, and genes) that affect or impact the process of HR DNA repair. The kit uses GFP as an in vivo readout for the HR pathway and Crispr-CAS gRNA plasmid that drives a DS DNA break in Cassette 1. This DS break induces HR in a mutated GFP reporter gene, which recombines with Cassette 2 containing WT GFP leading to GFP+ cells after completing HR. - Product type: variable - Product categories: Cell Context DNA Repair, Homologous Recombination Reporter Cells - Product tags: DNA Repair, Homologous Recombination, HR DNA Reporter - Product shipping classes: Domestic Dry Ice - Product Cell Context DNA Repair: Homologous Recombination Reporter Cells This is a HeLa cell-based reporter kit designed to allow the customer to screen or identify agents (drugs, natural products, small molecules, synthetics, miRNAs, and genes) that affect or impact the process of HR DNA repair. The kit uses GFP as an in situ readout for the HR pathway. - Product type: variable - Product categories: TPD2 Products - Product tags: Tdp2, Tyrosyl DNA Phosphodiesterase 2 - Product shipping classes: Domestic Room Temperature - Product TPD2 Products: TPD2 Substrate Tyrosyl-DNA phosphodiesterase-2 (TDP2) functions to remove trapped topoisomerase II/DNA complexes by processing 5′- blocking protein (topo II) at the site of the DNA break. - Product type: variable - Product categories: TPD2 Products - Product tags: Tdp2, Tyrosyl DNA Phosphodiesterase 2 - Product TPD2 Products: Human TPD2 Tyrosyl-DNA phosphodiesterase-2 (Human TDP2) functions to remove trapped topoisomerase II/DNA complexes by processing 5′- blocking protein (topo II) at the site of the DNA break. In terms of physiological relevance, there appear to be multiple roles for TDP2, well beyond the repair of type II topoisomerase damage and subsequent DNA repair. - Product type: variable - Product categories: TPD2 Products - Product tags: Human Tdp2 Assay, Tdp2, Tyrosyl DNA Phosphodiesterase 2 - Product shipping classes: Domestic Room Temperature - Product TPD2 Products: Human TPD2 Assay Kit TDP-2 is a relatively recently discovered repair protein. TDP2 (unlike TDP1) is specifically directed to act on phosphotyrosyl bonds that form when topoisomerase II is covalently trapped on the DNA helix. This Kit is designed to assay Human TDP-2 activity using a novel, non-radiolabeled substrate constructed as a huTop2/DNA covalent complex (CC) intermediate. - Product type: simple - Product categories: TDP1 Products - Product tags: Tdp1, Tdp1 Antibody, Tyrosyl DNA Phosphodiesterase 1 - Product shipping classes: Domestic Room Temperature - Product TPD1 Products: Polyclonal AB to Human TDP1 A rabbit polyclonal antibody was prepared against the native Tdp1 protein. The purity was greater than 99% as determined by SDS-PAGE. The antibody is in solution (PBS) at 2. 5 unit/ul (see definitions of unit below). This antibody is ideal for Western blotting applications or immunoflourescent (IF) studies on the cytological localization. The dilutions of antibody required for specific detection should be optimized for the investigator’s particular system (cell line being used for example). - Product type: variable - Product categories: TDP1 Products - Product tags: Human Tdp1, Tdp1, Tyrosyl DNA Phosphodiesterase 1 - Product shipping classes: Domestic Blue Ice - Product TPD1 Products: Human TPD1 TopoGEN provides purified Human Tyrosyl DNA Phosphodiesterase (Tdp1) purified to homogeneity to a single 68 kDa band on SDS-PAGE. Tdp1 is catalytically active and will remove a terminal 3’ phosphotyrosyl group from a specifically designed oligo target site (oligo-Tyr). - Product type: variable - Product categories: TDP1 Products - Product tags: Tdp1, Tdp1 Assay, Tyrosyl DNA Phosphodiesterase 1 - Product TPD1 Products: TPD1 Assay Kit The Tdp1 Assay Kit contains all reagents for routine detection of Tdp1 activity using the tyrosine release assay from the substrate Oligo-Tyr (human tdp1 is sold separately). The assay is highly specific for Tdp1. - Product type: simple - Product categories: Topo Enzymes - Product tags: human top1, mutant human top1, top1, Topo 1, y723f - Product shipping classes: Domestic Dry Ice - Product Topo Enzymes: Mutant Human Topo I TopoGEN now offers a catalytically inactive form of mutant human topoisomerase I purified to homogeneity (single band on SDS-PAGE). The mutation is a single residue change at the active site tyrosine (which has been changed to phenylalanine). This preparation is overexpressed in baculovirus and affinity purified as a single band on SDS-PAGE of 100 kDa. The enzyme cannot relax DNA (but still binds to DNA) and contains a short (6 residue) histidine tag. - Product type: variable - Product categories: Topo Enzymes - Product tags: human top2, top2a, topo2, topoisomerase 2 alpha - Product shipping classes: Domestic Dry Ice - Product Topo Enzymes: Human Topo IIA We purify Human Topoisomerase IIα (Top2a) using a proprietary method developed by the staff at TopoGEN. The purified enzyme is completely free of contamination and nucleases. It alters linking number of a unique topoisomer in steps of two and the major polypeptide detected on SDS-PAGE is 170 kDa. - Product type: simple - Product categories: Topo II, Topoisomerase Related Drugs - Product tags: adriacin, dox, doxorubicin - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Topo II TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase II. For in vitro cleavage detection, we recommend that the drug be tested over a wide range of uM concentrations; however, cleavages are strongly influenced by the amount of topoisomerase in the reaction as well as the type of assay being employed (SDSK+ vs. Radioactive End Labeled DNA vs. testing for plasmid cleavages). Note that large amounts of enzyme will be required to detect cleavage complex, compared to assays that measure catalytic activity. - Product type: simple - Product categories: Topo II, Topoisomerase Related Drugs - Product tags: amsacrine, mamsa - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Topo II TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase II. For in vitro cleavage detection, we recommend that the drug be tested over a wide range of uM concentrations; however, cleavages are strongly influenced by the amount of topoisomerase in the reaction as well as the type of assay being employed (SDSK+ vs. Radioactive End Labeled DNA vs. testing for plasmid cleavages). Note that large amounts of enzyme will be required to detect cleavage complex, compared to assays that measure catalytic activity. - Product type: simple - Product categories: Topo II, Topoisomerase Related Drugs - Product tags: daunomycin - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Topo II TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase II. - Product type: simple - Product categories: Topo II, Topoisomerase Related Drugs - Product tags: genistein - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Topo II Genistein is an isoflavone and an inhibitor of tyrosine protein kinases. It has been reported to induce topo II dependent cleavages. - Product type: simple - Product categories: Topo II, Topoisomerase Related Drugs - Product tags: etoposide, top2 inhibitor, top2 poison, topo 2 control, vp16 - Product shipping classes: Domestic Room Temperature - Product Topo Related Drugs: Topo II TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase II. For in vitro cleavage detection, we recommend that the drug be tested over a wide range of uM concentrations; however, cleavages are strongly influenced by the amount of topoisomerase in the reaction as well as the type of assay being employed (SDSK+ vs. Radioactive End Labeled DNA vs. testing for plasmid cleavages). Note that large amounts of enzyme will be required to detect cleavage complex, compared to assays that measure catalytic activity. - Product type: simple - Product categories: Topo II, Topoisomerase Related Drugs - Product tags: anti top2 inhibitor, hu331 - Product Topo Related Drugs: Topo II HU-331 is a cannabinoid-based quinone with potential anticancer activity. - Product type: simple - Product categories: Topo II, Topoisomerase Related Drugs - Product tags: ellipticine - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Topo II Ellipticine is a topoisomerase II poison that induces topo II dependent cleavages. - Product type: simple - Product categories: Gyrase and Topo IV, Topoisomerase Related Drugs - Product tags: cipro, ciprofloxacin, dna gyrase control, topo 4 control - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Gyrase & Topo IV A control poison/inhibitor of DNA Gyrase and Topo IV. This is also included in the Topo IV/Gyrase Drug Screening Kits. - Product type: simple - Product categories: Topo I, Topoisomerase Related Drugs - Product tags: camptothecin, rubitecan - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Topo I 20(S)camptothecin has shown promising activity against a range of tumour types. This CPT derivative causes cell toxicity by stabilizing a ternary complex between the nuclear enzyme topoisomerase I (topo I) and double-stranded DNA, leading to single and double strand breaks. TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase I. - Product type: simple - Product categories: Topo I, Topoisomerase Related Drugs - Product tags: camptothecin, topo 1 poison - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Topo I Camptothecin is a topo I poison that both inhibits enzyme activity and stabilizes formation of topo I cleavage complexes (Hsiang et al J. Biol. Chem. 260:14873-14878, 1985). TopoGEN provides this reagent as a control inhibitor/poison of topoisomerase I. - Product type: simple - Product categories: Topoisomerase Related Drugs - Product tags: cpt11, irinotecan - Product shipping classes: Domestic Blue Ice Irinotecan (CPT-11) Description Irinotecan (also known as CPT-11) is a water soluble, semi-synthetic analogue of 20(S)camptothecin (CPT) with promising activity against a range of tumour types. Irinotecan causes cell toxicity by stabilizing a ternary complex between the nuclear enzyme topoisomerase I (topo I) and double-stranded DNA, leading to single and double strand breaks. TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase I. For in vitro cleavage detection, we recommend that the drug be tested over a wide range of uM concentrations; however, cleavages are strongly influenced by the amount of topoisomerase in the reaction as well as the type of assay being employed (SDSK+ vs. Radioactive End Labeled DNA vs. testing for plasmid cleavages). Note that large amounts of enzyme will be required to detect cleavage complex, compared to assays that measure catalytic activity. - Product type: simple - Product categories: Topo I, Topoisomerase Related Drugs - Product tags: camptothecin - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Topo I 9-Amino-20-(R,S)-camptothecin (also known as 9-amino campthecin) is an analogue of camptothecin. Like other CPT congeners, it shows some promising activity against a range of tumor types. This compound causes cell toxicity by stabilizing a ternary complex between the nuclear enzyme topoisomerase I (topo I) and double-stranded DNA, leading to single and double strand breaks. TopoGEN provides this reagent as a control poison/inhibitor of topoisomerase I. - Product type: simple - Product categories: Topo I, Topoisomerase Related Drugs - Product tags: hycamtin, topotecan - Product shipping classes: Domestic Blue Ice - Product Topo Related Drugs: Topo I Hycamtin (topotecan hydrochloride) is a semi-synthetic derivative of camptothecin and is an anti-tumor drug that targets topo I and is a topo I poison (induces cleavage complexes). - Product type: simple - Product categories: DNA Substrates - Product tags: kdna marker, linear kdna, linear kdna marker - Product shipping classes: Domestic Room Temperature - Product DNA Substrates: Linear kDNA Marker Assays employing crude extracts for topo II activity based upon relaxation of supercoiled DNA can be complicated due to the presence of topo I in partially purified fractions. Additional complications arise with contaminating nuclease activity (due to Mg++) which degrade or nick the supercoiled substrate. These problems can be avoided by using a catenated DNA substrate prepared from the kinetoplast of the insect trypanosome Crithidia fasciculata. - Product type: simple - Product categories: DNA Substrates - Product tags: decatenated kdna, decatenated kdna marker, kdna marker, topo 2 assay - Product shipping classes: Domestic Room Temperature - Product DNA Substrates: Decatenated kDNA Marker Assays employing crude extracts for topo II activity based upon relaxation of supercoiled DNA can be complicated due to the presence of topo I in partially purified fractions. Additional complications arise with contaminating nuclease activity (due to Mg++) which degrade or nick the supercoiled substrate. These problems can be avoided by using a catenated DNA substrate prepared from the kinetoplast of the insect trypanosome Crithidia fasciculata. KDNA is an aggregate of interlocked DNA minicircles (mostly 2. 5 kb) that form extremely large networks of high molecular weight. - Product type: variable - Product categories: DNA Substrates - Product tags: dna substrate, phot1, relaxed dna substrate, relaxed phot1 - Product DNA Substrates: Relaxed pHOT-1 Relaxed pHOT-1 DNA is suited to assaying the supercoiling activity of DNA gyrase. It is also useful for assaying alterations in DNA linking number for assessing intercalation. - Product type: variable - Product categories: DNA Substrates - Product tags: dna substrate, phot1, phot1 dna, supercoiled dna substrate, supercoiled phot1 - Product shipping classes: Domestic Room Temperature - Product DNA Substrates: Supercolied pHOT-1 Supercoiled pHOT-1 plasmid is the perfect substrate for assaying any topoisomerase, although it was developed for Topo I because it has a top1 high affinity binding site. Why do we call it pHOT-1? It’s because we are the only company to offer a supercoiled plasmid DNA substrate engineered to attract and drive the process of top1 relaxation and cleavage. SC pHOT-1 is relatively small ( - Product type: variable - Product categories: DNA Substrates - Product tags: DNA gyrase, kdna, kdna substrate, kinetoplast dna, topo2 - Product DNA Substrates: kDNA Kinetoplast DNA (kDNA) is the ideal substrate for topoisomerase II assays because it is specific for type II reaction mechanisms. Researchers can even assay for a type II enzyme in the presence of large excess of topoisomerase I. Thus, kDNA works well to quantify type II activity in crude cell extracts, which are frequently overloaded with topoisomerase I. kDNA works exceptionally well with human Top 2a and b as well as prokaryotic enzymes, such as DNA Gyrase or Topoisomerase IV. This substrate is packaged with our Topo II Assay Kit, Topo II Drug Screening Kit, and Gyrase Assay Kits. - Product type: simple - Product categories: Protein MW Markers, Topo Antibodies - Product tags: top1, topo 1 marker, western blot marker - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Protein MW Markers The Western blot marker set for topo I is used to unambiguously locate the position of the 100 kDa form of intact topo I. This product is supplied in SDS-PAGE loading buffer and ready to load directly onto an SDS-PAGE. - Product type: simple - Product categories: Protein MW Markers, Topo Antibodies - Product tags: human topo 2, top2 marker, top2a - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Protein MW Markers The marker set for topo II is used to unambiguously locate the position of the 170 kDa topo II in Western Blots. The human 170 kDa is present in SDS-PAGE loading buffer. Note that human topo II may break down spontaneously with prolonged storage or with repeated freezing and thawing cycles. TopoGEN, Inc. stipulates that the marker be 90% undegraded at the time of shipment. - Product type: simple - Product categories: Antibody Kits, Topo Antibodies, Topo Kits - Product tags: human topo 2, immunofluorescence kit, topo 2 - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Antibody Kits This assay kit contains all the reagents for cytolocalization of Human Top2a using immunofluorescence. The system is optimized for use with FITC or Rhodamine labeled secondary antibody with adherent cells. The method may work with other cells besides human. Mouse, rat and monkey cells will cross react with topo II antibody. The antibody is specific for p170 (topo II alpha). - Product type: simple - Product categories: Topo Antibodies, Topo III Antibodies - Product tags: human topo 3, human topo 3 ab, monoclonal antibody - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Topoisomerase III Antibodies This monoclonal antibody was raised against purified recombinant protein and is specific for the C-terminal region (residues 748-976). The antibody is not ideal for use in western blotting experiments but will work on slot blot applications. It is well suited for immunohistochemistry with paraffin embedded tissue using 1:25 to 150 dilutions, the high temperature unmasking procedure and standard ABC techniques. It will work with frozen tissue although acetone fixation is recommended. We generally recommend 60 min incubation at 25 C for the primary antibody. Specific conditions used in each lab may vary as will specific applications for this AB. For this reason, the conditions for detecting nuclear and nucleolar localization should be worked out emperically in each laboratory. - Product type: simple - Product categories: Topo Antibodies, Topo III Antibodies - Product tags: human topo 3, human topo 3 ab, polyclonal antibody - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Topoisomerase III Antibodies A rabbit polyclonal antibody was prepared against a pool of oligopeptides derived from the carboxy terminal region of human topoisomerase IIIb. The purity of the peptides was greater than 95% as determined by HPLC and mass spectral analysis. Approximately 10 mg of purified peptide were coupled (through a terminal cysteine thiol) to KLH with a heterobifunctional cross-linking agent MBS at a ratio of 1 part peptide to 1 part KLH. The antibody titer was determined by ELISA to be > 1:10000. This antibody is ideal for Western blotting applications but has not been tested for other applications. The dilutions of antibody required for specific detection should be optimized for the investigator’s particular system (cell line being used for example). - Product type: simple - Product categories: Topo Antibodies, Topo II Antibodies - Product tags: human topo 2, monoclonal antibody, topo 2 alpha ab - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Topoisosomerase II Antibodies Mouse monoclonal antibody prepared against an oligopeptide derived from the C-terminus of the p170 kDa human Topoisomerase II Alpha. The antibody was then affinity purified over a column containing the same peptide. - Product type: simple - Product categories: Topo Antibodies, Topo II Antibodies - Product tags: polyclonal antibody, topo 2 ab, yeast Topo 2 ab - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Topoisosomerase II Antibodies This is a highly specific antibody, sold as crude serum (not affinity purified) that will neutralize enzymatic activity of yeast topoisomerase II. The antibody is specific for S. cerevisiae and does not cross react on Western blots with the human or calf thymus enzymes. Although this reagent may be suitable for use in immunofluorescent applications, it has not been characterized for such applications. - Product type: simple - Product categories: Topo Antibodies, Topo II Antibodies - Product tags: human topo 2, polyclonal antibody, topo 2 beta ab - Product shipping classes: Domestic Room Temperature - Product Topo Antibodies: Topoisosomerase II Antibodies This rabbit polyclonal antibody is directed specifically against the C-terminus of purified topo IIb. - Product type: simple - Product categories: Topo Antibodies, Topo II Antibodies - Product tags: human topo 2, polyclonal antibody, topo 2 alpha ab - Product shipping classes: Domestic Room Temperature - Product Topo Antibodies: Topoisosomerase II Antibodies Rabbit Polyclonal Antibody to Human Topoisomerase II Alpha was prepared against a 16 residue oligopeptide derived from the carboxy terminal region of human topoisomerase II. The purity of the peptide was greater than 95% as determined by HPLC and mass spectral analysis. The antibody titer was determined by ELISA to be > 1:104. Immunoaffinity gel chromatography and antibody purification steps were carried out to obtain a homogeneously purified IgG. - Product type: simple - Product visibility: outofstock - Product categories: Topo Antibodies, Topo II Antibodies - Product tags: human topo 2 beta, monoclonal antibody, topo 2 beta ab - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Topoisosomerase II Antibodies This mouse monoclonal antibody is directed specifically against purified Topo IIb. Because the two isoforms are very close in MW, we demonstrate by band shifting analysis combined with Westerns that this antibody reacts predictably with the Beta isoform (Fig. 1). - Product type: simple - Product categories: Topo Antibodies, Topo II Antibodies - Product tags: peptide, topo 2, topo 2 alpha peptide - Product shipping classes: Domestic Room Temperature - Product Topo Antibodies: Topoisosomerase II Antibodies This vial contains a 16 residue oligopeptide derived from the carboxy terminal region of human topoisomerase IIa. The purity of the peptide was greater than 95% as determined by HPLC and mass spectral analysis. Approximately 10 mg of purified peptide were coupled (through a terminal cysteine thiol) to KLH with a heterobifunctional cross-linking agent MBS at a ratio of 1 part peptide to 1 part KLH. The peptide was used to immunize rabbits for antibody production. The resulting antibody reacts strongly and specifically with the 170 kDa Human Topo II protein. This peptide is used as a control reagent in immunofluorescence; it effectively neutralizes the antibody to topo II. - Product type: simple - Product categories: Topo Antibodies, Topo I Antibodies - Product tags: human topo 1 antibody, polyclonal antibody, topo 1 ab, topo 1 ab patient serum - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Topoisomerase I Antibodies The immunoglobulin fraction was purified from scleroderma patients and shown to react specifically with the 100 kDa form of Topo I using Western blotting. The antibody is particularly useful as a Western blotting probe and can be used at high dilutions (>1:5,000). Cross reactivity of this antibody with other species has been demonstrated (with calf thymus). - Product type: simple - Product categories: Topo Antibodies, Topo I Antibodies - Product tags: human topo 1 antibody, monoclonal antibody - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Topoisomerase I Antibodies This monoclonal antibody was raised to human topo I (TG2005H-RC1) using standard methods. The antibody (IgG class) works very well for Western blotting experiments. The epitope has not been mapped. This product has not been tested for IP or IF applications; however, given the high specificity seen on Westerns, it should work well in these applications. - Product type: simple - Product categories: Topo Antibodies, Topo I Antibodies - Product shipping classes: Domestic Blue Ice - Product Topo Antibodies: Topoisomerase I Antibodies Antibody was raised to human topo I (purified from placenta) using New Zealand White rabbits. Serum was collected and processed using standard methods. The antibody can be used in Western blotting. Cross reactivity of this antibody with other species has not yet been tested. It is important to note that human topoisomerase I undergoes spontaneous degradation especially with repeat freezing/thawing. The activity of the enzyme is not affected significantly; however, sub-bands may be detectable in Western blotting experiments. - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: k glu, potassium glutamate - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments 5X Potassium Glutamate (1ml). - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: topo 4, topo 4 assay buffer - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments Topo IV Assay Buffer is supplied as a 5x Stock solution in two parts that must be mixed prior to use: These two buffers must be mixed to prepare a final 5x complete Topo IV Assay Buffer (A+B) as follows: add 0. 1 volume of Buffer B to 1. 0 volume Buffer A. Prepare only as much of the complete Topo IV Assay Buffer (A+B) as needed for each day or set of experiments. Note that this buffer should be kept on ice and used the same day, then discarded. - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: topo 2, topo 2 dilution buffer - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments Topo II Dilution Buffer is supplied as a working solution at 1X solution. The buffer is optimized and tested for use as a diluent for TopoGEN’s type II topoisomerase. - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: pro k, proteinase k - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments Proteinase K is a subtilisin-like endolytic protease that is isolated from the saprophytic fungus Tritirachium album. It has a high activity that is stable across a wide range of pH and temperature conditions and is suited to short digestion times. The activity of proteinase K is increased at elevated temperatures up to 65° C. Calcium is not essential to the function of proteinase K. Therefore, EDTA and other chelating agents do not interfere with the activity and may be used alongside proteinase K to inactivate calcium-dependent nucleases in DNA and RNA preparation. - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: dna gyrase assay buffer, EC DNA Gyrase - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments E. coli DNA gyrase assay buffer supplied as a 5X stock solution. The buffer is optimized and tested for E. coli DNA gyrase only. - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: 20% Sarkosyl - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments 20% Sarkosyl - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: gel load buffer - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments Vial contains 1ml of 10X agarose gel loading buffer ( 0. 005% bromophenol blue, 50% glycerol). - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: sds, sodium dodecyl sulfate - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments High purity SDS is dissolved in triple glass distilled/deionized, sterile water to 10% (w/v). The ability of each lot to function as an effective topoisomerase denaturant is tested and verified for each lot. - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: stop buffer - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments Is used to terminate topoisomerase reactions. To terminate reactions, add 1/5 volume to the reaction prior to loading agarose gel. - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: 20mM atp, atp - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments 20mM ATP supplied in aqueous buffer (0. 5ml). - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: human top1, top 1 dilution buffer, top1, topo 1 dilution buffer - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Kit Replenishments Topo I Dilution Buffer is supplied as a working solution at 1X solution. The buffer is optimized and tested for use as a diluent for recombinant human topoisomerase I enzyme from TopoGEN. - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: human top2, top2a, topo 2 assay buffer, topo2 - Product shipping classes: Domestic Room Temperature Topo II Buffer is supplied as a 10x Stock solution in two parts that must be mixed prior to use: 10X Incomplete Topo II Assay Buffer A contains the following: 0. 5M Tris-HCl (pH8. 0), 1. 5M NaCl, 0. 1M MgCl2, 5 mM dithiothreitol. 10X ATP Buffer B contains 20 mM ATP in water. These two buffers must be mixed to prepare a final 5X working stock of assay buffer. Furthermore, the final 5X Complete Buffer contains both A and B and should be made fresh for each experiment. Do not freeze the 5X Complete Buffer; it is stable for 24 hours on ice. To Prepare the 5X Complete Buffer, mix equal volumes of A and B (0. 1ml of A and 0. 1ml of B) and place at 4° C or on ice. - Product type: simple - Product categories: Kit Replenishments, Topo Kits - Product tags: sa dna gyrase, sa dna gyrase assay buffer, saureus dna gyrase - Product shipping classes: Domestic Room Temperature - Product DNA Substrates: Buffer - Product Topo Kits: Kit Replenishments S. Aureus Gyrase Assay Buffer (1ml). - Product type: variable - Product categories: Topo Kits - Product tags: Cell Context Screens, ICE assay, ice assay kit - Product shipping classes: Domestic Room Temperature - Product Topo Kits: ICE Assay Kit High throughput In vivo Complex of Enzyme (ICE) Assay that measures endogenous topoisomerase/genomic DNA covalent complexes. The one day procedure does not require a CsCl centrifugation step. The ICE Assay Kit is topo specific since we provide antibody that corresponds to the topo/DNA complex. - Product type: variable - Product categories: Drug Screening Kits - Product tags: top1, topo 1 assay, topoisomerase 1 - Product shipping classes: Domestic Dry Ice - Product Drug Screening Kits: Topo I Hi-Loading Inhibition Kit This kit is designed to allow the customer to screen for agents (drugs, natural products, small molecules, synthetics) that block the catalytic activity of human topoisomerase I (topo I). The use of high stoichiometric ratios of topo I:DNA induces cleavage complexes without the need to use topo I poisons (camptothecin) which facilitates detection of catalytic inhibitors of topoI. The assay (see ref 1) is based on the finding that topo I acts in a cooperative manner on DNA template, whereby it tends to display clustered activity (at neighboring sites, see ref 3); thus, at high ratios of enzyme:DNA, it is relatively easy to detect nicking by topo I in the absence of topo I poisons like camptothecin and its various congeners. - Product type: variable - Product categories: Drug Screening Kits - Product tags: DNA gyrase, drug screening, EC DNA Gyrase, gyrase - Product Drug Screening Kits: Gyrase This kit is designed to screen for novel gyrase targeting drugs, either as interfacial poisons (or IFPs that induce cleavage of DNA) Catalytic inhibitory compounds (CICs that block gyrase action by any number of mechanisms). It is a straight forward gel assay kit that is easily adopted. This kit contains purified bacterial (E. coli) DNA Gyrase purified to homogeneity (>98% based on SDS-PAGE), as well as substrate relaxed DNA (plasmid pHOT1). - Product type: variable - Product categories: Drug Screening Kits - Product tags: drug screening, ec top4, ecoli top4, topo 4 drug screening kit - Product Drug Screening Kits: Topo IV The Topoisomerase IV Drug Screening Kit contains reagents necessary to identify compounds that affect enzyme activity. Note that kits with a catalog number denoted -A will include E. coli topoisomerase IV enyzme. - Product type: variable - Product categories: Drug Screening Kits - Product tags: 1009, drug screening, phot1, supercoiled dna substrate, TG1009, Top2 Drug Screening Kit, topo 2 drug screening kit - Product Drug Screening Kits: Topo II Topoisomerase II Drug Screening Kit is a cleavage based detection assay that will reveal whether a particular agent either antagonizes the action of topo II or affects the cleavage/religation cycle. - Product type: simple - Product categories: Topo Kits - Product tags: nuclear extraction kit, topo 2 nuclear extraction kit - Product shipping classes: Domestic Room Temperature - Product Topo Kits: TopII-NucEx Kit TopII-NucEx Kit is designed to allow a researcher to prepare a nuclear extract enriched for topoisomerase II (top2) activity. The appropriate assay buffer specific for topo II is included. - Product type: simple - Product categories: Topo Kits - Product tags: nuclear extraction kit, topo 1 nuclear extraction kit - Product shipping classes: Domestic Room Temperature - Product Topo Kits: TopI-NuEx Kit TopI-NucEx Kit is designed to allow a researcher to prepare a nuclear extract enriched for topoisomerase I (top1) activity and intact 100 kDa polypeptide. The appropriate assay buffer specific for topo I is included. - Product type: variable - Product categories: Topo Kits - Product tags: DNA gyrase, dna gyrase relaxed dna assay kit, EC DNA Gyrase, ecoli dna gyrase, gyrase - Product shipping classes: Domestic Dry Ice - Product Topo Kits: Gyrase & Relaxed DNA Assay Kit Designed to provide the investigator quick and specific assays for DNA Gyrase. - Product type: simple - Product categories: Topo Kits - Product tags: dna intercalator, dna intercalator kit, dna unwinding kit, intercalator kit - Product shipping classes: Domestic Room Temperature - Product Topo Kits: DNA Unwinding Kit The purpose of the DNA Intercalator/Unwinding Kit is to determine if a compound induces DNA unwinding characteristic of DNA intercalators. Sufficient materials are provided for at least 50 independent determinations. NOTE: enzyme is not included with this kit. - Product type: simple - Product categories: Topo Kits - Product tags: DNA gyrase, EC DNA Gyrase, gyrase assay - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Gyrase Assay Kit The Kit is designed to allow quick and specific detection of DNA gyrase. This kit facilitates the purification and characterization of type II topoisomerase enzymes (DNA Gyrase) and contains all reagents necessary for routine assays of type II enzymes that either have or do not have the ability to supercoil. - Product type: variable - Product categories: Topo Kits - Product tags: human topo 2, top2a, topo 2, topo 2 assay, topo 2 assay kit - Product shipping classes: Domestic Room Temperature - Product Topo Kits: Topo II Assay Kit This kit is designed to allow quick and specific assays for any type II topoisomerase, either eu- or prokaryotic. This kit facilitates the purification and characterization of type II enzymes and contains all reagents necessary for routine assays of Topoisomerase II. - Product type: variable - Product categories: Topo Kits - Product tags: 1015, human top1, human topo 1 assay kit, TG1015, Top1 Assay, topo 1 assay - Product Topo Kits: Topo I Assay Kit Human Topoisomerase I Assay Kit contains all the necessary reagents for routine detection of Topoisomerase I activity. The included DNA markers allow unequivocal detection of the enzyme. The assay is specific for topoisomerase I enzyme; (eukaryotic type II topoisomerases require MgCl2 and ATP). - Product type: variable - Product categories: Drug Screening Kits - Product tags: drug screening, human top1, topo 1 drug screening kit - Product shipping classes: Domestic Dry Ice - Product Drug Screening Kits: Topo I The Topo I Drug Kit is designed to allow the investigator to quickly identify novel inhibitors of Human Top1. It will allow detection of novel compounds that either stabilize the nicked intermediate or otherwise inhibit catalytic activity of topoisomerase I. This kit is ideal for pharmaceutical researchers, academic scientists, and biotech professionals seeking to develop and characterize new therapeutic agents targeting Topoisomerase I. Your browser does not support the video tag. ## Posts - Categories: News, News Research, Reviews & Articles - Tags: DNA Repair, DNA Topoisomerases A remarkable new study from investigators at the National Institutes of Health has uncovered an unexpected mechanism underlying one of chemotherapy's most debilitating side effects: cisplatin-induced peripheral neuropathy. Rather than DNA repair simply protecting neurons, the researchers found that DNA repair itself can become toxic when neurons lack sufficient deoxynucleotide (dNTP) pools to complete the repair process. Their work shows that nucleotide excision repair (NER) begins removing cisplatin-induced DNA lesions normally. However, because mature neurons maintain very low intracellular dNTP pools, repair frequently stalls before completion. The result is accumulation of DNA breaks, neuronal death, and ultimately peripheral neuropathy. The exciting discovery is that replenishing cellular nucleotide pools—either by supplying deoxynucleosides or genetically increasing intracellular dNTP levels—dramatically improved neuronal survival and reduced neuropathy in animal models. A broader implication While this work focused on cisplatin, it raises an intriguing question that extends well beyond platinum chemotherapy. Many anti-cancer agents—including topoisomerase poisons—produce DNA lesions that must also be repaired by the cell. Could insufficient nucleotide pools similarly limit repair in vulnerable post-mitotic tissues such as: peripheral neurons cardiac muscle cochlear cells other non-dividing tissues If so, transient enhancement of nucleotide availability might reduce treatment-associated toxicity while preserving anti-tumor efficacy. Where TopoGEN fits These questions require robust methods to measure DNA damage, repair, and drug mechanism. TopoGEN's portfolio—including ICE® Assays, purified human topoisomerases, DNA repair reagents, and mechanistic drug screening platforms—provides researchers with the tools needed to explore precisely these types of questions. As oncology moves toward maximizing efficacy while minimizing toxicity,... - Categories: News, News Research, Reviews & Articles - Tags: human topoisomerase II, Topo IIb, Topoisomerase drug discovery OK, this paper actually has massive implications for topoisomerase drug discovery because it challenges a long-standing assumption about TOP2 poisons. Rather than simply trapping the cleavage complex (as etoposide does), the authors propose that their modified epipodophyllotoxin derivative actively dismantles the TOP2β catalytic apparatus, producing an irreversible, religation-defective complex that leads to persistent DNA double-strand breaks. Topoisomerase II enzymes remain among the most important targets in cancer chemotherapy, yet clinically successful drugs such as etoposide are limited by drug resistance and treatment-associated toxicities. A recently published study in the International Journal of Biological Macromolecules reports a potentially important advance in TOP2 drug discovery through the characterization of a novel 4β-S-DMEP derivative that inhibits human TOP2β through an unexpected mechanism. Using crystallography, biochemical analysis, and computational modeling, the investigators discovered that the compound induces a unique “open-state” TOP2β cleavage complex that is incapable of DNA religation. Unlike classical TOP2 poisons that primarily stabilize the cleavage complex, this agent appears to promote disruption of the catalytic phosphotyrosyl linkage itself, effectively dismantling the enzyme’s religation machinery and driving the formation of persistent DNA double-strand breaks. The study provides one of the clearest structural views yet of how rational modifications to the epipodophyllotoxin scaffold can dramatically alter topoisomerase biology. Importantly, the work suggests a path toward next-generation TOP2-targeted therapeutics designed to overcome resistance mechanisms that limit conventional agents. At TopoGEN, we recognize that breakthroughs such as these depend upon access to high-quality topoisomerases, validated DNA substrates, and robust mechanistic assay systems capable of distinguishing... - Categories: News, News Research, Reviews & Articles - Tags: Cancer Research, DNA Repair, Drug Discovery, Topoisomerase A newly published study in Molecular Cell highlights an exciting advance in topoisomerase biology and potential cancer therapeutics. Importantly, this work was enabled using topoisomerase reagents and assay technologies supplied by TopoGEN. Konada and colleagues report that Heat Shock Factor 1 (HSF1) selectively stimulates the catalytic activity of DNA topoisomerase IIβ (TOP2β) while exerting minimal effects on the closely related TOP2α isoform. The authors demonstrate that HSF1 physically associates with TOP2β, enhances its DNA cleavage and relaxation activities, and promotes TOP2β engagement with chromatin. In contrast, TOP2α is largely unaffected. These findings are especially significant because TOP2 poisons such as etoposide and doxorubicin remain among the most important anti-cancer agents in clinical oncology. While these drugs effectively kill rapidly dividing cancer cells, they also produce serious long-term toxicities. Increasing evidence suggests that many of these adverse effects—including cardiotoxicity and therapy-related secondary malignancies—are mediated primarily through TOP2β rather than TOP2α. The study further demonstrates that HSF1 inhibitors reduce TOP2β activity and protect post-mitotic cells from TOP2 poison-induced damage while preserving anti-tumor activity in proliferating cells. This raises the intriguing possibility that selective modulation of the HSF1–TOP2β axis could someday be used to reduce the cardiac and neurological side effects associated with topoisomerase-targeted chemotherapy without compromising therapeutic efficacy. For the topoisomerase field, this work provides a new mechanistic framework for understanding isoform-selective regulation and opens the door to strategies that may separate anti-cancer activity from dose-limiting toxicity. TopoGEN is proud that its reagents and expertise continue to support groundbreaking discoveries that advance... - Categories: News, News Research, Reviews & Articles - Tags: DNA Repair, DNA Topoisomerases, Topo Drug Screening A new study published in Nature Structural & Molecular Biology provides important insights into how cells repair DNA damage arising from collapsed replication forks—one of the most significant threats to genome stability and a key driver of cancer, aging, and genetic disease. The authors demonstrate that repair outcomes differ dramatically depending on whether a single replication fork collapses or whether converging forks fail simultaneously, revealing previously unappreciated complexity in DNA damage response pathways. (Nature) Studies such as this rely heavily on the ability to generate, detect, and characterize DNA strand breaks and topological intermediates that arise during DNA replication and repair. DNA topoisomerases are central players in these processes, regulating DNA supercoiling, replication fork progression, chromosome segregation, and the resolution of DNA entanglements. (Springer Nature Experiments) TopoGEN is proud to support the global DNA replication and repair community with specialized topoisomerase enzymes, DNA substrates, antibodies, screening kits, and assay systems designed specifically for mechanistic studies of genome stability. Our reagents have helped researchers worldwide investigate the molecular events that occur when replication forks stall, collapse, and are subsequently repaired—fundamental processes that underlie both cancer biology and therapeutic drug development. (3V Chimica) As this outstanding publication demonstrates, understanding the fate of damaged replication forks remains one of the most important frontiers in modern molecular biology. TopoGEN remains committed to providing the high-quality research tools that enable these discoveries. Conwell, S. C. , Patel, K. V. N. , Weeks-Pollenz, S. J. et al. Distinct repair outcomes from single and convergent replication fork... - Categories: News, News Research, Reviews & Articles A newly published study in Scientific Reports describes the identification and characterization of alternariol monomethyl ether (AME), a fungal secondary metabolite isolated from Alternaria alternata, with potent antiproliferative activity linked to inhibition of both DNA Topoisomerase I and II. Importantly, the investigators utilized TopoGEN’s plasmid relaxation and kDNA decatenation assay systems to quantify enzyme inhibition kinetics and demonstrate dual topoisomerase targeting activity. The study reported nanomolar inhibition of Topo II (IC50 10. 2 nM) and Topo I (IC50 16. 7 nM), accompanied by strong apoptosis induction and cell-cycle arrest in MCF-7 breast cancer cells. These findings further reinforce the value of robust biochemical topoisomerase assays in natural product drug discovery, mechanistic oncology research, and validation of emerging DNA damage-inducing compounds. We congratulate the authors on this elegant and comprehensive study. El-Sayed, A. S. A. , Aboelez, M. O. , Ezelarab, H. A. A. et al. Characterization of Alternaria alternata alternariol monomethyl ether with a potential antiproliferative activity by topoisomerases inhibition; molecular docking and dynamic simulations. Sci Rep 16, 15352 (2026). https://doi. org/10. 1038/s41598-026-51757-8 - Categories: News, News Research, Reviews & Articles - Tags: DNA Gyrase, E. coli DNA Gyrase Enzyme, Staph Aureus DNA Gyrase Enzyme There is an increasingly important enabling technology in gene therapy and nucleic acid delivery: the use of DNA Gyrase to generate highly supercoiled plasmid DNA, a topology that is strongly correlated with improved delivery efficiency and functional expression and enhanced efficiency in gene therapy. DNA gyrase, a bacterial Type II topoisomerase, is uniquely capable of introducing negative supercoils into closed circular DNA in an ATP-dependent manner, thereby compacting DNA and modulating its topology (Wikipedia). This structural state is not merely a biochemical curiosity—it has direct and measurable implications for gene delivery performance. A growing body of literature supports the importance of supercoiled DNA in therapeutic contexts: Supercoiled plasmid DNA demonstrates significantly higher transfection efficiency compared to relaxed or linear DNA forms, with relaxed DNA achieving only ~75% of the efficiency of supercoiled constructs. Recent studies show that engineered supercoiled DNA constructs yield markedly improved cellular uptake and expression in mammalian systems, including HeLa and muscle cell models (OUP Academic). Supercoiled DNA is also more resistant to physical stress (e. g. , shear, aerosolization), a key advantage for in vivo delivery platforms and formulation workflows (Nature). Process engineering strategies that enhance gyrase-mediated supercoiling have been explicitly proposed to improve plasmid quality for gene therapy applications (Analytical Science Journals). Mechanistically, supercoiling increases DNA compactness and reduces entanglement, facilitating cellular uptake, nuclear trafficking, and transcriptional accessibility—all critical parameters in both viral and non-viral delivery systems. At TopoGEN, we have seen firsthand the growing demand for high-quality DNA gyrase in this application space. Leading... - Categories: News, News Research, Reviews & Articles - Tags: AgingResearch, LongevityScience, TopoAssays Recent work published in Geroscience highlights an unexpected connection between topoisomerase inhibitors and longevity biology. Using a transcriptomics-driven discovery platform, researchers identified topoisomerase drugs (like amonafide) are a novel class of geroprotective agents. In C. elegans, these compounds improved mobility during aging and extended lifespan by activating conserved stress-response pathways, including the mitochondrial unfolded protein response (UPRmt). This is a striking shift in perspective: topoisomerase inhibitors traditionally viewed through an oncology lens (e. g. , Top2 poisons) may also modulate fundamental aging pathways linked to genome stability, mitochondrial signaling, and cellular defense programs! For those working at the interface of DNA topology, genome maintenance, and translational aging research, this opens many compelling opportunities & TopoGEN is uniquely positioned to enable and accelerate this line of investigation. Our portfolio of highly purified human topoisomerases (Top1, Top2α/β), DNA substrates (including kDNA), and mechanistic assay platforms (relaxation, decatenation, and ICE assays) allows researchers to: • Dissect **Top2-dependent vs. off-target drug mechanisms** • Quantify cleavage complex formation in cells (critical for “poison” vs. catalytic inhibitor classification) • Translate in vivo findings into **human-relevant biochemical and cellular systems** • Rapidly screen next-generation compounds for **geroprotective vs. genotoxic profiles** As the field moves from worm models toward human systems, **mechanistic clarity will be the gating factor**—and that is precisely where TopoGEN delivers. If you are exploring topoisomerases in aging, neurodegeneration, or genome stability, we welcome the opportunity to collaborate. #AgingResearch #LongevityScience #HealthyAging #DrugDiscovery #TopoGENCRO #TopoAssays #topoinhibitors GeroScience. 2025 Mar 14;47(3):5185–5204. doi: 10. 1007/s11357-025-01599-5 - Categories: News, News Research, Reviews & Articles The continued emergence of plant-derived bioactives as modulators of cancer biology is not new—but what is new is the increasing mechanistic clarity with which these compounds are being evaluated. A recent study published in Phytomedicine (2026) highlights this shift, demonstrating how a traditional herbal formulation enhances anti-melanoma efficacy through defined molecular pathways, including DNA damage response modulation and chemotherapeutic sensitization. The authors report two key mechanistic effects. First, suppression of MGMT, a primary driver of TMZ resistance. Second, inhibition of Chk1, a central regulator of replication stress and the DNA damage response. This combination is powerful. When you impair DNA repair and simultaneously disable checkpoint control, you push cancer cells toward replication catastrophe. Here’s the part that often gets missed. These conditions are highly permissive for topoisomerase-mediated DNA damage. Even though the paper does not directly interrogate topoisomerases, the biology strongly suggests increased persistence of Topoisomerase I and II cleavage complexes, elevated torsional stress during replication, and a higher probability of lethal DNA strand breaks. In other words, DNA topology becomes the battleground. What would strengthen this study further is direct mechanistic confirmation at the enzyme level. In a TopoGEN-style workflow, this is where we would extend the findings. Specifically, incorporating a Topoisomerase II decatenation assay using a system such as the TopoGEN Topoisomerase II Assay Kit would allow clear determination of whether the formulation acts as a Topo II poison, functions as a catalytic inhibitor, or indirectly increases Topo II–mediated DNA damage through disruption of the DNA damage response.... - Categories: News, News Research, Reviews & Articles A newly published study in the Journal of Molecular Biology (2026) provides important mechanistic insight into how tyrosyl-DNA phosphodiesterase I (Tdp1) processes topoisomerase-mediated DNA damage—extending its functional relevance beyond its classical role in Top1 repair and into the Top2 space. This work is particularly notable because it challenges long-standing assumptions about repair pathway specificity and reinforces a broader biological principle observed in DNA topology systems: functional compensation and redundancy. Key Scientific Takeaways Topoisomerases operate through transient covalent intermediates—Top1 forming 3′-phosphotyrosyl linkages and Top2 forming 5′-phosphotyrosyl linkages. Stabilization of these intermediates (e. g. , by camptothecin or etoposide) converts essential enzymes into cytotoxic DNA lesions. Traditionally: Tdp1 → resolves Top1-DNA adducts (3′ linkages) Tdp2 → resolves Top2-DNA adducts (5′ linkages) However, this study demonstrates that Tdp1 can process Top2-DNA covalent complexes under specific conditions, particularly when complexes are stabilized and partially processed. Compensatory Biology: A Familiar Theme in Topoisomerase Systems This finding aligns with a well-established concept from yeast and other eukaryotic systems: topoisomerases themselves exhibit functional compensation. Classic genetic studies in Saccharomyces cerevisiae have shown that: Loss or mutation of Top1 can be partially tolerated due to compensatory activity from Top2 Conversely, Top2 deficiencies can be buffered—though incompletely—by Top1 under certain conditions While not functionally identical, these enzymes can redistribute topological stress relief, allowing cells to survive perturbations in one pathway. Extending the Concept to DNA Repair: Tdp1 as a Backup System The new data suggest that Tdp1 may operate under a similar compensatory framework: When canonical Top2 repair (via... - Categories: News, News Research, Reviews & Articles (Based on Sookai et al. , Eur. J. Med. Chem. 287 (2025) 117330) A new publication in the European Journal of Medicinal Chemistry reports a surprising and important discovery about how certain gold(III) compounds interact with human topoisomerase IIα (Top2α)—and the work was made possible using TopoGEN products. The study reveals that one of these pyrrole-based gold complexes (AuL1) acts as a classic interfacial poison of Top2α, but only within a defined concentration window. At low–mid micromolar levels, AuL1 traps the Top2 cleavage complex effectively, generating abundant linearized DNA. But as concentrations increase, its mechanism flips: the same compound becomes a catalytic inhibitor, blocking enzyme access to DNA entirely. This biphasic, bell-shaped activity profile is striking—and it underscores a principle TopoGEN has long emphasized: Single-point drug screens miss critical mechanistic behavior. A Top2-active compound may appear inactive at one concentration, yet display strong poisoning activity at another. Only through titration-based assays—such as TopoGEN’s industry-standard Top2α relaxation and cleavage complex platforms—can these nuanced modes of action be revealed. The following TopoGEN kits are designed precisely for these types of analyses: Human Topoisomerase II Assay Kit Human Topoisomerase II Drug Screening Kit (kDNA Based) Both kits have variants available with and without Top2α. As the authors clearly demonstrate, this gold compound shows potent mechanistic switching that would have been invisible in a simple one-dose screen. For anyone developing Top2α targeted therapeutics, this is a powerful reminder: mechanism matters, dose matters, and TopoGEN assays expose what other approaches overlook. At TopoGEN, we bring... - Categories: News, News Research A new Nature Communications study is reshaping how scientists think about the origins of cancer-causing mutations. The research focuses on a DNA-managing enzyme called TOP2B (topoisomerase IIβ)—an essential “stress-relief” protein that helps untangle DNA so genes can be switched on. Until now, TOP2B was mostly viewed as a helpful regulator of transcription. But this new work shows something far more dramatic: TOP2B sits right at the center of many of the mutational hotspots that drive cancer. By examining actual human tumors, the researchers mapped exactly where TOP2B binds across the genome. What they discovered is striking—the enzyme frequently marks regions where dangerous DNA events occur, including double-strand breaks, structural rearrangements, and the very mutations that push cells toward cancer. These hotspots are most common at hyper-active promoters, enhancers, and the architectural “loop anchors” that help fold DNA in 3-dimensional space. Even more compelling, the study found that TOP2B-binding sites near major cancer genes—TP53, MYC, FOXA1, VHL, and even the non-coding driver RMRP—carry some of the highest burdens of mutations and structural variants. This strongly suggests that normal TOP2B activity, when misregulated or stressed, can unintentionally contribute to cancer genome evolution. Why This Matters—and How TopoGEN Enables This Frontier Research Understanding how topoisomerases create or influence mutations is becoming central to modern cancer biology. That’s why TopoGEN’s technologies are uniquely suited to advance this research. Our ICE Assays, TOP1/TOP2 cleavage-complex detection kits, and functional drug-testing platforms allow scientists to: Pinpoint enzyme-mediated DNA damage Quantify trapped cleavage complexes Identify new therapeutic strategies... - Categories: News, News Research, Reviews & Articles A groundbreaking new Nature study reveals that cancer cells use specialized genomic “retention elements” to preserve and propagate extrachromosomal circular DNA (ecDNA)—a major engine of oncogene amplification and tumor evolution. These circular ecDNAs, which lack centromeres and segregate randomly, should theoretically be lost at each cell division. Yet this work shows that cancer cells have evolved a mechanism to tether ecDNA to mitotic chromosomes, ensuring their inheritance and continued oncogenic drive. The authors identify thousands of CpG-rich retention sequences, often hypomethylated, that interact with mitotic “bookmarking” proteins to hitchhike ecDNA into daughter cells. Hypomethylation is crucial—when these CpG sites were experimentally methylated, ecDNA failed to tether properly and was lost. This establishes a powerful epigenetic axis: hypomethylation enables ecDNA persistence; methylation disrupts retention and reduces tumor viability. Another major insight: these molecules are circular, megabase-scale structures that frequently incorporate multiple retention elements. Circular DNA is highly susceptible to topological strain, supercoiling, and the enzymatic actions of DNA topoisomerases, which modulate DNA winding and relieve torsional stress. The presence of circular oncogenic ecDNA therefore strongly suggests that Top1 and Top2 enzymes are functionally engaged in their replication, segregation, and maintenance. Targeting these enzymes—already validated anticancer strategies—may be even more impactful when extrachromosomal circular DNA biology is considered. Why this Matters for Cancer Therapeutics and for TopoGEN Users If ecDNA is a primary engine of oncogenesis, and if its circular structure depends on topoisomerase activity, then topo-based therapeutics (Top1 and Top2 poisons, catalytic inhibitors, and combination therapies) may help destabilize the very... - Categories: News, News Research, Reviews & Articles A major Cell paper has uncovered a completely new layer of DNA repair biology: cells use selective autophagy and lysosomes to process and remove Topoisomerase I cleavage complexes (TOP1cc)—the toxic DNA–protein crosslinks created during normal replication and when cells are exposed to TOP1-targeting drugs like camptothecin. According to the Cell article (2024), researchers discovered that: Lysosomes actively degrade TOP1cc in vertebrate cells, providing a previously unknown repair pathway that protects genome stability. This mechanism operates at clinically relevant, low doses of CPT, not the high doses traditionally used to study proteasomal TOP1cc turnover. TEX264 acts as the autophagy receptor for TOP1cc, detecting trapped complexes at replication forks and mediating their delivery to lysosomes through p97 and ATR-dependent signaling. The nuclear envelope transiently remodels to allow TOP1cc export from the nucleus to the lysosome—a remarkable trafficking event visualized through live-cell and cryo-EM imaging. Autophagy-driven TOP1cc clearance is essential for cell survival, directly influencing clinical sensitivity to TOP1-targeted chemotherapeutics. In short: Topoisomerase I cleavage complexes aren’t just repaired—they’re trafficked, recognized, and selectively destroyed through a dedicated autophagy pathway. This discovery changes our understanding of TOP1 pharmacology and opens a path toward therapeutics that modulate TOP1cc turnover. Why This Matters for TopoGEN and Cutting-Edge Anti-Cancer Research This new biology—TOP1cc recognition, export, and lysosomal destruction—cannot be studied or exploited without sensitive, quantitative tools that detect TOP1cc directly in cells. And that is exactly what TopoGEN provides. TopoGEN’s ICE Assay (In Vivo Complex of Enzyme) is the essential tool that enables research like this. The... - Categories: News, News Research, Reviews & Articles Heterocephalus glaber What if the secret to slowing human aging isn’t a mystery at all, but a DNA repair trick stolen from a strange little creature that lives underground? A new Science paper just revealed something jaw-dropping: Naked mole-rats (also known as the sand puppy ) live ~40 years because their DNA repair machinery is turbo-charged (longest living rodent on the planet). Just four amino acids in their version of the cGAS protein dramatically boost double-strand break repair through the HR pathway. This keeps their genomes stable, delays organ decline, suppresses senescence, and — yes — slows biological aging. Think about that: Longevity isn’t magic. It’s DNA repair efficiency. And here is where it gets even more exciting... If evolution can re-wire DNA repair to extend lifespan in a rodent, then we can interrogate — and potentially modulate — those same pathways in human cells. That’s exactly where TopoGEN steps in. Our HR and NHEJ DNA Repair Reporter Kits allow scientists to: • Map Repair efficiency in any cell line • Discover new anti-aging therapeutics • Identify genetic or epigenetic factors affecting genome stability • Screen compounds that shift cells toward healthier, more resilient repair programs Aging touches every single human on Earth — and its root cause may be deeply tied to how well your cells fix their DNA. If you are working on longevity, cancer, genome maintenance, senescence, or drug discovery: TopoGEN can provide you with the tools to measure, modulate, and understand the pathways that evolution used... - Categories: News, Reviews & Articles They Said This Breast Cancer Was Untouchable. Now It’s 70% Gone! This is why TopoGEN is a key player, providing tools that allow anti-cancer drug discovery and facilitate such important findings. Scientists have designed a new “smart bomb” drug, DM1, that obliterates the deadliest form of breast cancer—triple-negative breast cancer—by hitting two critical targets at once. DM1 latches onto DNA and an overactive cancer protein (TOP2A), shattering tumor cells’ genetic code while sparing healthy tissue. In lab and animal tests, DM1 stopped tumor growth by over 70%, more than doubling the effect of a standard chemo drug (also a topo drug), with fewer side effects. This breakthrough could pave the way for powerful, low-toxicity treatments against cancers that defy today’s therapies. Let us know how we can help in your drug discovery journey! https://www. sciencedirect. com/science/article/abs/pii/S0223523425008062 - Categories: News - Formats: Image Are you working with agents that target Human Top1? This short video discusses the use and relevance of Our Topoisomerase I Drug Screening Kit. Learn how to quickly identify novel inhibitors of Human Top1. - Categories: News What does TopoGEN do, exactly? We're so glad you asked! Check out this video for the TopoGEN backstory, a glimpse at our lab space, and in particular Dr. Muller's vision for attracting more like-minded tech to Buena Vista, Colorado. Huge shout out to the Central Colorado SBDC for putting this together! - Categories: News TopoGEN products (Top2a) were used in the following study published in Nature. This is a very exciting and powerful result suggesting novel inroads to addressing the problem of cardiotoxicity. In this work, authors develop obex inhibitors that target a distinct binding pocket in the ATPase domain of Topoisomerase II. They demonstrate how Topobexin, a Topoisomerase IIβ - selective catalytic inhibitor, blocks conformational changes and protects against anthracycline cardiotoxicity. Let us know how we can help you with your drug development R&D when designing testing and validating novel topo drugs! We are a group of experienced investigators in the topo field and a reliable CRO. Topobexin targets the Topoisomerase II ATPase domain for beta isoform-selective inhibition and anthracycline cardioprotection - Categories: News, News Research, Reviews & Articles Transfection-based Homologous Recombination (HR) and Non-homologous End Joining (NHEJ) kits use transient transfections to make a pool of cells containing the DNA reporters to allow the investigator to interrogate the 2 major DNA repair pathways. The advantages are: It uses GFP readout to measure the efficiency of repair. There is zero background when repair is blocked or inhibited The reporters for HR or NHEJ can be installed in virtually any cell line that can be transiently transfect It is rapid and robust It is ideal for drug screens to find novel inhibitors of HR/NHEJ The kits are highly specific and can only report HR or NHEJ Readout GFP can be done by FACS or Imaging Entire pathway can be followed by live imaging in viable cells Ideal to track repair kinetics at the single cell level https://www. youtube. com/watch? v=XeBAICuV0Uc&embeds_referring_euri=https%3A%2F%2Fdnarepairkits. com%2F&source_ve_path=OTY3MTQ - Categories: News Contract Screening Services Exciting News from TopoGEN, Inc. We are thrilled to announce the launch of our groundbreaking screening tool, the **IQ Screen** This novel and affordable tool is designed specifically for researchers seeking a rapid go/no-go decision on which compounds to advance as anti-topoisomerase agents. IQ stands for “Insight Quick” and is ideal for labs that want a quick and mechanism based decision flow on which drugs are most promising and which should be low priority. Why Choose IQ Screen for my drug development needs? – Speed: Get quick results to accelerate R&D output. – Cost-Effective: Affordable solutions for every research budget. – Tractable: Easy-to-use and integrate into your existing workflows. – Mechanism-Based. We can parse the inhibitors from the poisons... . two foundational mechanisms of action. – IQ Screen is Applicable to human Topoisomerases I and 2 (both a & b isoforms) and bacterial enzymes. – All inclusive. No hidden or extra fees. – Certified. We guarantee cosmetic, publication quality data that is your own IP – NDA built in. Your company will own our work product exclusively. We do this to accelerate the paperwork and get you the data right away. Our innovative IQ Screen not only saves you time and resources but also ensures efficient optimization from hit to lead. Our dedicated scientists are here to assist you every step of the way, providing rapid turnaround times and revealing mechanisms of action for your unknown anti-cancer therapeutics. You will work with a Ph. D. project director... - Categories: News Research Contract Screening Services Experience. Rapid Turn-Around. Publication Quality. TopoGEN has >20 yrs. experience in the area as a Contract Research Organization and we stand behind our results. We guarantee clear, cosmetic data and unambiguous interpretations. You will receive a publication quality product. We are seasoned veterans in the arena of in vitro testing. More importantly, we can help you develop a tractable strategy for analysis of drug mechanisms in the context of the tumor cell. We can evaluate potential genotoxicity independently from topo effects without extra charge. Finally, all our topo enzymes are homogeneously pure. We do not screen using extracts. Controls with specific drugs (e. g. , etoposide vs. Topo IIa) guarantee specificity in all assays and validate even negative results with unknowns. We find and validate valuable hits and optimize hit to lead results. Our strength is our experience with a wide variety of prokaryotic and eukaryotic topos and related pathway proteins. Competitive pricing and publication quality results, guaranteed. We save our clients considerable time and labor by offering services that are designed as a multi-tier approach to testing. For example, a limited scope screen (3-5 concentration inputs) is reasonable to quickly assess potential targeting. If the results are clearly negative, there is no need for follow-up. If we obtain a hit/lead, we will work closely with you to design next logical steps in a tier -2 testing strategy. In all cases, we will craft a strategy with you to move ahead or not. Our screens are designed... - Categories: Reviews & Articles - Tags: health, nature - Formats: Image The anthracycline antibiotics doxorubicin (Adriamycin; DOX) and daunorubicin (DNR) continue to be essential components of first-line chemotherapy in the treatment of a variety of solid and hematopoietic tumors. The overall efficacies of DOX and DNR are, however, impeded by serious dose-limiting toxicities, including cardiotoxicity, and the selection of multiple mechanisms of cellular drug resistance. These limitations have necessitated the development of newer anthracyclines whose structural and functional modifications circumvent these impediments. In this review, we will present recent strategies in anthracycline design and assess their potential therapeutic merits. Current anthracycline design has diverged to target either cytoplasmic or nuclear sites. Nuclear targets have been broadened to include not only topoisomerase II (topo II) inhibition through ternary complex stabilization and catalytic inhibition, but also topoisomerase I (topo I) inhibition and transcriptional inhibition. In contrast, cytoplasmic targeting focuses on anthracycline binding to protein kinase C (PKC) regulatory domain with consequent modulation of activity. Drug Resist Updat. 2001 Jun; 4(3): 169-77. Department of Pharmacology, The University of Tennessee Health Science Center, Memphis 38163, USA. Lothstein L, Israel M, Sweatman TW. llothstein@utmem. edu - Categories: Reviews & Articles - Tags: medicine, research - Formats: Image The nuclear enzyme DNA topoisomerase II (topo II) is the target of important antitumor agents such as etoposide. Recent work has classified topo II targeting drugs into either topo II poisons that act by stabilizing enzyme-DNA cleavable complexes leading to DNA breaks, or topo II catalytic inhibitors that act at stages in the catalytic cycle of the enzyme where both DNA strands are intact and, therefore, do not cause DNA breaks. Accordingly, catalytic inhibitors are known to abrogate DNA damage and cytotoxicity caused by topo II poisons. In this commentary, we have focused on the possibilities of enabling high-dose therapy with the topo II poison etoposide by protection of normal tissue with catalytic inhibitors, analogous to folinic acid rescue in high-dose methotrexate treatment. Thus, we have demonstrated recently that (+)-1,2-bis(3,5-dioxopiperazinyl-1-yl)propane (ICRF-187) enabled a 3- to 4-fold dose escalation of etoposide in mice. Two high-dose etoposide models are described, namely use of the weak base chloroquine in tumors with acidic extracellular pH and targeting of CNS tumors with protection of normal tissue by the bisdioxopiperazine ICRF-187. In conclusion, high supralethal doses of topo II poisons in combination with catalytic inhibitor protection form a new strategy to improve the antitumor selectivity of etoposide and other topo II poisons. Such an approach may be used to overcome problems with drug resistance and drug penetration. Biochem Pharmacol. 1997 Oct 1; 54(7): 755-9. Laboratory of Experimental Medical Oncology, Finsen Center, Copenhagen, Denmark. Jensen PB, Sehested M. - Categories: Reviews & Articles - Tags: lab, News - Formats: Video This review presents a summary of preclinical and clinical data on the topoisomerase I (topo I) inhibitors that are under clinical development. To date, all of the topo I inhibitors that have been clinically evaluated are analogues of camptothecin, an extract of the Chinese tree Camptotheca acuminata. The therapeutic development of camptothecin was initially limited by its poor solubility and unpredictable toxicity. More recently, a number of water-soluble camptothecin analogues have undergone extensive evaluation and have demonstrated significant clinical activity. These include irinotecan (CPT-II), topotecan, and 9-aminocamptothecin (9-AC). Preliminary data are also reviewed on other camptothecin analogues (GG-211 and DX-8951f), on oral formulations, and on non-camptothecin topoisomerase I inhibitors. The topoisomerase I inhibitors have already demonstrated a broad spectrum of antitumour activity, most probably due to their unique mechanism of action and lack of clinical cross-resistance with existing antineoplastic compounds. The challenge for the next five years is to identify ways to integrate the topo I inhibitors into multidrug and multimodality therapies to achieve optimal antitumour effect, while keeping the side effects of these therapies manageable. Ann Oncol. 1997 Sep; 8(9): 837-55. Division of Medical Oncology, University of Texas Health Science Center at San Antonio, USA. Rothenberg ML. - Categories: Reviews & Articles - Tags: medicine, research - Formats: Image The standard treatment of multiple myeloma is systemic chemotherapy. Despite 30 years of drug development in myeloma, there are no new drug regimens significantly superior to melphalan and prednisone. In addition, phase II studies of new drugs in myeloma have been disappointing, with low response rates and no prolongation in survival. The topoisomerase I (topo I) inhibitors are a new class of anticancer agents with a wide spectrum of activity in human malignancies. Recent evaluation of the topo I inhibitor topotecan demonstrated activity in advanced myeloma, suggesting a possible role for these drugs in the treatment of this disease. Further evaluation of the mechanisms of resistance to topo I inhibitors, study of combination therapy with topotecan, and evaluation of other topo I poisons in multiple myeloma is proposed. Semin Hematol. 1998 Jul; 35(3 Suppl 4): 32-8. Division of Hematology-Oncology and Arthur G. James Cancer Hospital and Research Institute, Ohio State University, Columbus 43210-1240, USA. Kraut EH, Ju R, Muller M. - Categories: Reviews & Articles - Tags: News, tech - Formats: Image Camptothecin (CPT) class of compounds has been demonstrated to be effective against a broad spectrum of tumors. Their molecular target has been firmly established to be human DNA topoisomerase I (topo I). CPT inhibits topo I by blocking the rejoining step of the cleavage/religation reaction of topo-I, resulting in accumulation of a covalent reaction intermediate, the cleavable complex. The primary mechanism of cell killing by CPT is S-phase-specific killing through potentially lethal collisions between advancing replication forks and topo-I cleavable complexes. Collisions with the transcription machinery have also been shown to trigger the formation of long-lived covalent topo-I DNA complexes, which contribute to CPT cytotoxicity. Two novel repair responses to topo-I-mediated DNA damage involving covalent modifications of topo-I have been discovered. The first involves activation of the ubiquitin/26S proteasome pathway, leading to degradation of topo-I (CPT-induced topo-I downregulation). The second involves SUMO conjugation to topo-I. The potentials roles of these new mechanisms for repair of topo-I-mediated DNA damage in determining CPT sensitivity/resistance in tumor cells are discussed. Ann N Y Acad Sci. 2000; 922: 1-10. Department of Pharmacology, UMDNJ-Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA. Liu LF, Desai SD, Li TK, Mao Y, Sun M, Sim SP. lliu@umdnj. edu - Categories: Reviews & Articles - Tags: health, nature - Formats: Image While the majority of topoisomerase (topo) inhibitors show selectivity against either topo I or topo II, a small class of compounds can act against both enzymes. These can be divided into three classes. The first and largest class comprise drugs that bind to DNA by intercalation and include the clinically-evaluated acridine DACA, the benzopyridoindole intoplicine, the indenoquinolinone TAS-103, the benzophenazine XR11576, and the pyrazoloacridine NSC 366140. The second category comprises hybrid molecules, prepared by physically linking separate inhibitors of topo I and topo II, or by linking pure topo inhibitors to other DNA-interactive carriers. While several derivatives (e. g. , camptothecin-epipodophyllotoxin and ellipticine-distamycin hybrids) have been prepared, there have been no detailed studies. The third category are less well defined as a structural class, but apparently recognize structural motifs that are present in both topo I and II enzymes. These include a series of benzoisoquinolinium quaternary salts such as NK 109, and more interestingly modified versions of classical topo I or topo II inhibitors; e. g. , the modified camptothecin BN 80927 and the modified epipodophyllotoxin tafluposide (F-11782). There is as yet no detailed understanding of the factors that result in selective or dual inhibition, but structure-activity studies in several classes show that structural changes can influence topo I/II selectivity. DNA intercalation mode also appears to play a part. The basis for the high antitumor activity of some topo inhibitors is not yet understood but may depend on the complex pattern of activities that include both inhibition and poisoning of... - Categories: Reviews & Articles - Tags: medicine, research - Formats: Image Natural and synthetic indolocarbazole compounds have triggered considerable interest since the discovery in 1986 of the inhibitory properties of staurosporine toward protein kinase C (PKC). Later, it has been shown that indolocarbazole compounds may inhibit various kinases, such as cyclin dependent-kinases and/or topoisomerase I, someones behave only as DNA intercalators. In this review are presented various indolocarbazole compounds bearing a sugar moiety and their biological targets. The relevance of these targets to develop indolocarbazole compounds as potential antitumor agents is discussed. Curr Med Chem Anti-Canc Agents. 2004 Nov;4(6):509-21. Related Articles Laboratoire SEESIB, UMR 6504 CNRS, Universite Blaise Pascal, 24, Avenue des Landais, 63177 Aubiere, France. Prudhomme M. mprud@chimie. univ-bpclermont. fr - Categories: Reviews & Articles - Tags: creative, environment - Formats: Image The genomic era has shifted anticancer drug development from its traditional mode concentrated on natural product cytotoxic agents to mechanism-based drug design focused on signal transduction pathways. Yet traditional cytotoxic chemotherapies continue to have an important role in the armamentarium. This is particularly true when one considers that important elements of solid tumor physiology – acidosis and hypoxia – have rarely been incorporated into algorithms for anticancer drug development. It is now well established that a majority of solid tumors exist in an acidic and hypoxic microenvironment that promotes resistance to radiation and chemotherapies apart from any drug-induced target mutations or efflux protein pumps. The acidic extracellular environment leads to a pH gradient unique to tumor cells. This gradient will favor uptake and retention of small molecule drugs that are weak acids. The converse is true for weak bases. The camptothecin class of topoisomerase I inhibitors is one example of a natural product cytotoxic that can exploit the tumor pH gradient. Screening of compounds based on selective activity at acidic pH (pH modulation), rather than potency, reveals analogs that are over ten times more active under the acidic conditions prevalent in vivo. Thus, knowledge of the tumor metabolic phenotype gained at the beginning of the 20(th) century can lead to more effective anticancer drugs in the new millennium. Curr Med Chem Anti-Canc Agents. 2005 Jan;5(1):1-13. Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA. Adams DJ. adams041@mc. duke. edu - Categories: News - Tags: health, nature - Formats: Image Cell Context DNA Repair Kits Are you working on DNA-damage and repair? Would you be interested in a pre-validated cell-context system to analyze HR or NHEJ by single cell imaging or quantifying DNA repair by simple fluorescence? TopoGEN, Inc. has developed a suite of cell lines that will allow you to study specific DNA repair pathways in living cells. Our systems report specific Homologous Recombination (HR) well as Non-Homologous End Joining (NHEJ) pathways. These engineered cell lines are truly novel, giving unprecedented insight into HR and NHEJ at a single cell level of resolution. DNA repair is activated using an inducible DNA damage event directed specifically at a neutral reporter gene. Moreover, since only repaired cells become fluorescent, the investigator can follow each individual cell (and all descendants) by live imaging. We offer certified cell lines hosting both HR and NHEJ in human and mouse species. There are neuron specific and fibroblast hosting lines with other cell lineages under development (cardiac, kidney, NCI-60 lines, IPSCs). You can also provide us with your unique cell line to ‘host’ these repair systems (see our “Custom Services” program where we install an HR or NHEJ reporter in your specific cell line). Please contact us for a quote. - Categories: News - Tags: medicine, research - Formats: Image Experience. Rapid Turn-Around. Publication Quality. TopoGEN has >20 yrs. experience in the area as a Contract Research Organization and we stand behind our results. We guarantee clear, cosmetic data and unambiguous interpretations. You will receive a publication quality product. We are seasoned veterans in the arena of in vitro testing. More importantly, we can help you develop a tractable strategy for analysis of drug mechanisms in the context of the tumor cell. We can evaluate potential genotoxicity independently from topo effects without extra charge. Finally, all our topo enzymes are homogeneously pure. We do not screen using extracts. Controls with specific drugs (e. g. , etoposide vs. Topo IIa) guarantee specificity in all assays and validate even negative results with unknowns. We find and validate valuable hits and optimize hit to lead results. Our strength is our experience with a wide variety of prokaryotic and eukaryotic topos and related pathway proteins. Competitive pricing and publication quality results, guaranteed. We save our clients considerable time and labor by offering services that are designed as a multi-tier approach to testing. For example, a limited scope screen (3-5 concentration inputs) is reasonable to quickly assess potential targeting. If the results are clearly negative, there is no need for follow-up. If we obtain a hit/lead, we will work closely with you to design next logical steps in a tier -2 testing strategy. In all cases, we will craft a strategy with you to move ahead or not. Our screens are designed to reveal catalytic... - Categories: News - Tags: News, tech - Formats: Image July 20, 2018 TopoGEN was featured in the local press in order to showcase our collaboration with Nanoly Bioscience based out of Boulder. Nanoly has developed a polymer-based cage (the NanoShield) that can protect labile products from fluctuations in temperature and possibly obviate need for expensive dry ice transit around the world. TopoGEN is going to field test the NanoShield with our Human Topo I and garner end-user feedback via our extensive distribution network in Europe and Asia. This venture is being supported by funding from the SBIR program at NIH. Special thanks goes to the Chaffee County Times, the Mountain Mail, and Discover Colorado for their interest and support. Mtn Mail TG-Nanoly - Categories: Reviews & Articles Non-small cell lung cancer (NSCLC) is an aggressive disease that is generally resistant to chemotherapy. As a result, the prognosis for patients with NSCLC is poor. Currently, platinum-based regimens are the standard of care for patients with advanced NSCLC. However, these regimens are associated with severe and often cumulative hematologic and nonhematologic toxicities, limiting dose intensity. Therefore, novel chemotherapeutic agents and combination regimens may improve the outcome for these patients. A variety of new agents and combinations have been investigated in the treatment of NSCLC. However, to date, no clearly superior single-agent or combination regimen has emerged. Topotecan (Hycamtin; GlaxoSmithKline; Philadelphia, PA), a topoisomerase I inhibitor, is currently approved for the treatment of patients with relapsed small cell lung cancer (SCLC) and is associated with manageable, noncumulative, hematologic toxicities. In addition, topotecan demonstrates a favorable nonhematologic tolerability profile compared with agents currently used in the treatment of patients with NSCLC. The success of topotecan in patients with SCLC has made it an attractive option in the NSCLC setting. Topotecan-based combination regimens in the first-line treatment of NSCLC have demonstrated promising antitumor activities with favorable toxicity profiles. Many topotecan combination regimens have induced stable disease, a response that may offer meaningful clinical benefit in the palliative treatment of patients with advanced disease. Topotecan plus gemcitabine (Gemzar; Eli Lilly and Company; Indianapolis, IN) and single-agent topotecan may be particularly appropriate for patients in the second-line setting, in which palliation of symptoms is an important outcome of chemotherapy. Herein, the future role of... - Categories: Researches Experience. Rapid Turn-Around. Publication Quality. TopoGEN has >20 yrs. experience in the area as a Contract Research Organization and we stand behind our results. We guarantee clear, cosmetic data and unambiguous interpretations. You will receive a publication quality product. We are seasoned veterans in the arena of in vitro testing. More importantly, we can help you develop a tractable strategy for analysis of drug mechanisms in the context of the tumor cell. We can evaluate potential genotoxicity independently from topo effects without extra charge. Finally, all our topo enzymes are homogeneously pure. We do not screen using extracts. Controls with specific drugs (e. g. , etoposide vs. Topo IIa) guarantee specificity in all assays and validate even negative results with unknowns. We find and validate valuable hits and optimize hit to lead results. Our strength is our experience with a wide variety of prokaryotic and eukaryotic topos and related pathway proteins. Competitive pricing and publication quality results, guaranteed. We save our clients considerable time and labor by offering services that are designed as a multi-tier approach to testing. For example, a limited scope screen (3-5 concentration inputs) is reasonable to quickly assess potential targeting. If the results are clearly negative, there is no need for follow-up. If we obtain a hit/lead, we will work closely with you to design next logical steps in a tier -2 testing strategy. In all cases, we will craft a strategy with you to move ahead or not. Our screens are designed to reveal catalytic... - Categories: Researches - Tags: Cell Line Reporters, Homologous Recombination Repair Cell Line Reporters, HR based Kit, NHEJ based Kits Are you working on DNA-damage and repair? Would you be interested in a pre-validated cell-context system to analyze HR or NHEJ by single cell imaging or quantifying DNA repair by simple fluorescence? TopoGEN, Inc. has developed a suite of cell lines that will allow you to study specific DNA repair pathways in living cells. Our systems report specific Homologous Recombination (HR) well as Non-Homologous End Joining (NHEJ) pathways. These engineered cell lines are truly novel, giving unprecedented insight into HR and NHEJ at a single cell level of resolution. DNA repair is activated using an inducible DNA damage event directed specifically at a neutral reporter gene. Moreover, since only repaired cells become fluorescent, the investigator can follow each individual cell (and all descendants) by live imaging. We offer certified cell lines hosting both HR and NHEJ in human and mouse species. There are neuron specific and fibroblast hosting lines with other cell lineages under development (cardiac, kidney, NCI-60 lines, IPSCs). You can also provide us with your unique cell line to ‘host’ these repair systems (see our “Custom Services” program where we install an HR or NHEJ reporter in your specific cell line). Please contact us for a quote. - Categories: Researches - Tags: Cold Chain Logistics, Human Topoisomerase I, NanoShield, Topoisomerases & Enzymatic Activity July 20, 2018 TopoGEN was featured in the local press in order to showcase our collaboration with Nanoly Bioscience based out of Boulder. Nanoly has developed a polymer-based cage (the NanoShield) that can protect labile products from fluctuations in temperature and possibly obviate need for expensive dry ice transit around the world. TopoGEN is going to field test the NanoShield with our Human Topo I and garner end-user feedback via our extensive distribution network in Europe and Asia. This venture is being supported by funding from the SBIR program at NIH. Special thanks goes to the Chaffee County Times, the Mountain Mail, and Discover Colorado for their interest and support. Mtn Mail TG-Nanoly ## Research - Research Category: researches Contract Screening Services Experience. Rapid Turn-Around. Publication Quality. TopoGEN has >20 yrs. experience in the area as a Contract Research Organization and we stand behind our results. We guarantee clear, cosmetic data and unambiguous interpretations. You will receive a publication quality product. We are seasoned veterans in the arena of in vitro testing. More importantly, we can help you develop a tractable strategy for analysis of drug mechanisms in the context of the tumor cell. We can evaluate potential genotoxicity independently from topo effects without extra charge. Finally, all our topo enzymes are homogeneously pure. We do not screen using extracts. Controls with specific drugs (e. g. , etoposide vs. Topo IIa) guarantee specificity in all assays and validate even negative results with unknowns. We find and validate valuable hits and optimize hit to lead results. Our strength is our experience with a wide variety of prokaryotic and eukaryotic topos and related pathway proteins. Competitive pricing and publication quality results, guaranteed. We save our clients considerable time and labor by offering services that are designed as a multi-tier approach to testing. For example, a limited scope screen (3-5 concentration inputs) is reasonable to quickly assess potential targeting. If the results are clearly negative, there is no need for follow-up. If we obtain a hit/lead, we will work closely with you to design next logical steps in a tier -2 testing strategy. In all cases, we will craft a strategy with you to move ahead or not. Our screens are designed... Highly advanced laboratory It is a long established fact tha reader will be distracted by Comprehensive test menu It is a long established fact tha reader will be distracted by New age of biological alchemy Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pa atu sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollitanim ide enim ad minim veniam fugiat nulla pariatu sint occaecat cupidatat nonproid Sunt in culpa qui officia deserunt mollit Lorem ipsum dolor sit amet, consecte Sed do eiusmod tempor incidi secte Sunt in culpa qui officia deserunt mollit Lorem ipsum dolor sit amet, consecte Sed do eiusmod tempor incidi secte Highly advanced laboratory It is a long established fact tha reader will be distracted by Comprehensive test menu It is a long established fact tha reader will be distracted by New age of biological alchemy Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pa atu sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollitanim ide enim ad minim veniam fugiat nulla pariatu sint occaecat cupidatat nonproid Sunt in culpa qui officia deserunt mollit Lorem ipsum dolor sit amet, consecte Sed do eiusmod tempor incidi secte Sunt in culpa qui officia deserunt mollit Lorem ipsum dolor sit amet, consecte Sed do eiusmod tempor incidi secte Highly advanced laboratory It is a long established fact tha reader will be distracted by Comprehensive test menu It is a long established fact tha reader will be distracted by New age of biological alchemy Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pa atu sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollitanim ide enim ad minim veniam fugiat nulla pariatu sint occaecat cupidatat nonproid Sunt in culpa qui officia deserunt mollit Lorem ipsum dolor sit amet, consecte Sed do eiusmod tempor incidi secte Sunt in culpa qui officia deserunt mollit Lorem ipsum dolor sit amet, consecte Sed do eiusmod tempor incidi secte Highly advanced laboratory It is a long established fact tha reader will be distracted by Comprehensive test menu It is a long established fact tha reader will be distracted by New age of biological alchemy Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pa atu sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollitanim ide enim ad minim veniam fugiat nulla pariatu sint occaecat cupidatat nonproid Sunt in culpa qui officia deserunt mollit Lorem ipsum dolor sit amet, consecte Sed do eiusmod tempor incidi secte Sunt in culpa qui officia deserunt mollit Lorem ipsum dolor sit amet, consecte Sed do eiusmod tempor incidi secte Highly advanced laboratory It is a long established fact tha reader will be distracted by Comprehensive test menu It is a long established fact tha reader will be distracted by New age of biological alchemy Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pa atu sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollitanim ide enim ad minim veniam fugiat nulla pariatu sint occaecat cupidatat nonproid Sunt in culpa qui officia deserunt mollit Lorem ipsum dolor sit amet, consecte Sed do eiusmod tempor incidi secte Sunt in culpa qui officia deserunt mollit Lorem ipsum dolor sit amet, consecte Sed do eiusmod tempor incidi secte