A protocol for the in vitro micronucleus test. II. Contributions to the validation of a protocol suitable for regulatory submissions from an examination of 10 chemicals with different mechanisms of action and different levels of activity.

The in vitro micronucleus test is currently used as a screening assay during the early stages of drug development by pharmaceutical companies to identify chemicals likely to produce positive outcomes in the in vitro chromosome aberration assay. For several reasons the assay is being considered as an alternative to the aberration assay-it requires less laboratory time, less material and less training. However, the current screening protocols are not rigorous enough to fully satisfy concerns about genotoxic safety.

A protocol for the in vitro micronucleus test. I. Contributions to the development of a protocol suitable for regulatory submissions from an examination of 16 chemicals with different mechanisms of action and different levels of activity.

The in vitro micronucleus (IVM) test is currently used as a screen during the early stages of pharmaceutical development to identify chemicals likely to produce positive outcomes in the in vitro chromosome aberration assay. For several reasons, the assay is being considered as an alternative to the aberration assay, but the current screening protocols are not rigorous enough to fully satisfy concerns about genotoxic safety. This manuscript describes the investigation of several protocol parameters to assist with the development of a regulatory guideline for the IVM test.