Migration Groups: A Poorly Explored Point of View for Genetic Damage Assessment Using Comet Assay in Human Lymphocytes

A new point of view for genetic damage assessment using the comet assay is proposed based on the number of migration groups, the number of comets in each group, and the groups with the highest number of comets. Human lymphocytes were exposed to different concentrations of Methyl Methane Sulfonate (MMS), Maleic Hydrazide (MH), 2,4-Dichlorophenoxyacetic (2,4-D), and N-nitroso diethylamine (NDEA). Using comet assay, the migration means of the comets were determined and later grouped arbitrarily in migration groups with no higher differences than 1 µc. The number of migration groups, the number of comets in each group, and the groups with the highest number of comets (modes) were determined. All four of the genotoxic agents studied showed a significant increase (p < 0.05) in the tail length and the number of migration groups compared to the negative control. The number of migration groups did not show a significant variation between the four-genotoxic agents nor within their different concentrations. However, the comparison of the modes did show differences between the genotoxic agents, but not within the concentrations of a same genotoxic agent, which indicated a determined chemical interaction on the DNA. These parameters can improve the detection of genetic damage associated with certain genotoxic agents.