The chromosome aberration test (CAT) is designed to evaluate the potential of a test compound to induce structural chromosomal abnormalities such as breaks and exchanges.
Screening and Regulatory Support
- The CAT can be performed in primary human peripheral blood lymphocytes (HPBL) or established cell lines, such as Chinese hamster ovary (CHO) cells.
- Cultures are incubated with several concentrations of the test compound for 3 to 4 hours in the presence and absence of metabolic activation (S9) and for 21 hours in the absence of S9.
- A positive outcome is characterized by a statistically significant, dose-dependent increase in aberrant cells that exceeds historical negative control limits.
Metaphase spread of human lymphocyte showing multiple chromosome aberration
When to Perform
- IND-enabling studies
- As part of the ICH S2(R1) standard battery
- REACH requirement
- As part of Annex VIII testing