Testing Chemical Agents with the Cytokinesis-Block Micronucleus Cytome Assay (C3Acells/genotoxicity/chemicalmutagens/spindlepoisons/clastogens/enzymeinhibitors)

In order to evaluate the applicability of the cytokinesis-block micronucleus cytome assay in rou- tine mutagenicity testing we investigated with this method different chemicals having different mecha- nisms of action: non-mutagens, direct-acting base- altering mutagens, direct-acting cross-linking muta- gens, clastogens including a radiomimetic chemical, indirect-acting spindle poisons and indirect-acting enzyme inhibitors. We looked at the presence of mi- cronuclei as biomarkers for either the loss of chro- mosome fragments (clastogen) or the loss of a whole chromosome (aneugen), nucleoplasmic bridges as biomarkers for complex rearrangements (e.g., dicen- tric chromosomes) and nuclear buds as biomarkers for gene amplification. The cytome assay proved to be a suitable tool to investigate genetic effects of en- vironmental agents and to provide insight into their working mechanisms as all chemicals tested showed the expected response.