Genotoxicity assays are a core component of in vitro toxicology services because they assess a compound’s potential to damage genetic material, which can lead to mutations, cancer, or heritable genetic defects.
Purpose: To assess whether a compound can cause genetic damage such as DNA mutations, chromosomal alterations, or aneuploidy. These changes can result in carcinogenesis, heritable genetic defects, or developmental toxicity. Early detection of genotoxic potential is critical to ensuring drug safety, meeting regulatory standards, and guiding compound selection during drug discovery and development. These in vitro assays are faster, lower-cost, and reduce reliance on animal testing.
TME Scientific’s genotoxicity assay capabilities.
| Assay | Principle | Application | FDA Context |
|---|---|---|---|
| Ames Test (Bacterial Reverse Mutation Assay) | Detects point mutations in bacterial DNA (with and without metabolic activation) | First-line screen for mutagenicity of chemicals and drug candidates | Required in most IND submissions; follows OECD TG 471 and ICH S2(R1) guidance |
| In Vitro Micronucleus Assay | Detects chromosome damage leading to micronucleus formation in dividing cells | Identifies clastogenic (breaks) and aneugenic (loss/gain) effects | FDA-accepted alternative to chromosomal aberration test; aligns with OECD TG 487 |
| Chromosomal Aberration Test (in vitro) | Detects structural chromosomal aberrations in cultured mammalian cells | Used to confirm clastogenic potential | Traditional assay under OECD TG 473; still accepted by FDA but micronucleus assay preferred |
| Mouse Lymphoma Assay (MLA) | Detects gene mutations and chromosomal damage in TK locus of L5178Y mouse lymphoma cells | Measures gene mutation, cytotoxicity, and clastogenicity simultaneously | Commonly used in pharma R&D; referenced under OECD TG 476 |
| In Vivo Micronucleus Assay | Detects chromosomal damage in bone marrow or peripheral blood of rodents after exposure | Confirms genotoxicity in vivo | Required when in vitro assays are positive; follows OECD TG 474 and ICH S2(R1) |
| Comet Assay (Single-Cell Gel Electrophoresis) | Measures DNA strand breaks in individual cells (tail formation under electrophoresis) | Mechanistic or follow-up tool for DNA damage | Not formally OECD-approved for regulatory use, but FDA accepts for mechanistic studies |