Should gaps be included in chromosomal aberration analysis? Evidence based on the comet assay.

This study evaluated DNA damage in human lymphocytes due to occupational exposure to low levels of ionizing radiation using two assays: the comet assay and chromosomal aberration (CA) analysis including and excluding gaps. The results obtained reveal a higher correlation between both methods when chromatid and chromosome gaps were included in the correlation analysis (r=0.78 versus r=0.50). This increased correlation support the hypothesis that the gaps constitute a type of chromosome aberration, and suggest that these events should be scored in this type of analysis.