Micronucleus assay in human cells: lymphocytes and buccal cells

The micronucleus (MN) assay, applied in different surrogate tissues, is one of the best validated cytogenetic techniques for evaluating chromosomal damage in humans. The cytokinesis-block micronucleus cytome assay (CBMNcyt) in peripheral blood lymphocytes is the most frequent method in biomonitoring human populations to evaluate exposure to genotoxic agents, micronutrient deficiency, or excess and genetic instability. Furthermore recent scientific evidence suggests an association between an increased MN frequency in lymphocytes and risk of cancer and other age-related degenerative diseases. The micronucleus cytome assay applied in buccal exfoliated cells (BMNCyt) provides a complementary method for measuring DNA damage and cytotoxic effects in an easily accessible tissue not requiring in vitro culture. The protocol for CBMNcyt described here refers to the use of ex vivo whole blood involving 72 h of culture with the block of cytokinesis at 44 h. BMNCyt protocol reports the established method for sample processing, slide preparation, and scoring.