CHROMOSOME ABERRATION TESTING IN GENETIC TOXICOLOGY - PAST, PRESENT AND FUTURE

In vitro metaphase tests for chromosomal aberrations (CA) have undergo ne considerable evolutionary changes over the last 20 yr. Treatment an d sampling times have been a particular focus of attention as we have tried. to develop protocols that detect weak genotoxins. Different app roaches evolved in different parts of the world and led to a need to h armonise. At the same time, we have increasingly challenged the condit ions in which clastogens produce positive responses, and several situa tions have been described in which clastogenic responses would be cons idered not to be biologically relevant. Now there is a strong case to replace the conventional metaphase analysis test with an in vitro micr onucleus test. The time is therefore right to carefully consider wheth er the type of damage scored in CA tests is relevant for human health. (C) 1998 Elsevier Science B.V. All rights reserved.