Micronucleus mechanistic follow-up
The in vitro micronucleus (MNvit) test is a genotoxicity test that investigates chromosome-damaging potential in mammals.
The in vitro test determines the number of micronuclei (MN) found in cells that have undergone cell division during or after exposure to the test chemical. Therefore, both clastogens and aneugens can be detected by this method.
In addition to using the MNvit test, the use of immunochemical labeling of kinetochores, or hybridization with centromeric/telomeric probes via fluorescence in-situ hybridization (FISH), can provide further information on the mechanisms of chromosome damage and MN formation.
The application of FISH probes can help to distinguish MN originating either from chromosome loss or breakage (i.e., aneugenic or clastogenic effects), and to determine the involvement of specific chromosomes and chromosome fragments in MN formation.