Introduction
Background information:
- Cyprotex offers the in vitro micronucleus test using fluorescent cellular imaging using CHO-K1 cells compliant to OECD Guidelines 487.
- High content screening (HCS) has several advantages over traditional manual methods – these include increased throughput, the removal of subjectivity through automated scoring, and the rapid measurement of large numbers of cells which increases statistical power.
- During cell division, if a chromosome or a fragment of a chromosome is not incorporated into one of the daughter nuclei, typically as a consequence of genetic damage, it may form its own “micronucleus”.
- Using HCS the in vitro micronucleus test simultaneously collects multiple endpoints including, relative survival (cell count), membrane integrity (cytotoxicity assessment) and cell cycle information (binucleated cell frequency and proliferation index (CBPI)). In combination these parameters determine cell health (cytostasis) and micronuclei validity.
- The assay delivers rapid multi-parametric assessment with the benefit of low compound requirements. In addition, the assay can detect genotoxins requiring metabolic transformation by utilizing induced rat liver S9.
- The micronucleus test complements other genotoxicity assays to provide a more mechanistic insight into genotoxicity. It also acts as a bridge to the in vivo micronucleus test required in the ICH guidelines.
Protocol
In Vitro Micronucleus Test Protocol
Data
Data from Cyprotex's In Vitro Micronucleus Test
References
1) Corvi R et al. (2008) ECVAM retrospective validation of in vitro micronucleus test (MNT). Mutagenesis 23(4); 271-283
2) OECD Guidelines for the testing of chemicals: In vitro Mammalian cell micronucleus test, July 2023 (#487)