The micronucleus assay is a widely used technique for detecting chromosomal damage in human cells, particularly lymphocytes and exfoliated buccal cells. This assay identifies micronuclei, which are small, extranuclear bodies containing chromosomal fragments or whole chromosomes that were not incorporated into the daughter nuclei during cell division. In human lymphocytes, the assay is typically conducted on cells stimulated to divide in culture, whereas in exfoliated buccal cells, it assesses naturally occurring cell samples. The micronucleus assay is valued for its simplicity, cost-effectiveness, and ability to provide insights into genotoxic exposure, genetic instability, and cancer risk. Its application in biomonitoring and epidemiological studies helps in evaluating the effects of environmental, occupational, and lifestyle factors on genetic material, thereby contributing to public health risk assessments and preventive strategies.