Cytokinesis Blocked Micronuclei Aberration Analysis.

Cytokinesis blocked micronuclei (CBMN) assay is a rapid and sensitive analysis of chromosome aberrations and miss assortments during cell division. Genotoxic agent exposure produces DNA damage and chromosome fragments. Fragmented chromosomes without centromere failed to attach kinetochore which segregates a pair of homologous chromosomes to each daughter cells at cytokinesis, hence leading to form micronuclei. Chromosome or fragments of chromosome can also form micronuclei when they are not accurately sorted to daughter cells. Using cytochalasin B, an actin inhibitor, blocks cytokinesis of which completion leads serration appearance formed with two daughter cells while nuclei segregation is undergoing. As a result, one cell having two daughter nuclei, i.e., binucleated cell, is produced. By analyzing these binucleated cells, chromosome aberrations can be estimated as well as popular chromosome aberration analysis. Frequency of micronuclei formation predicts the testing agents' genotoxicity. By combining use with centromere-specific probes or DNA damage signal probes, the nature of genotoxicity of tested agents can be estimated.