DETERMINATION OF RADIATION-INDUCED DAMAGE IN LYMPHOCYTES USING THE MICRONUCLEUS AND MICROGEL ELECTROPHORESIS COMET ASSAYS

DNA damage assays may be useful as rapid predictors of normal tissue r adiosensitivity in clinical samples. We measured in vitro radiation-in duced (2 Gy) damage to lymphocytes from cancer patients and normal hea lthy donors using both the micronucleus and microgel electrophoresis ( Comet) assays simultaneously. For damage assessment, there was a good correlation (P < 0.001) between the mean comet lengths and the fractio n of cells with comets. There was no correlation with initial damage, determined as the proportion of cells within a sample that formed come ts, in comparison with the mean frequency of micronuclei per binucleat e cell. However, there appeared to be an association between the deter mination of repair proficiency in the Comet assay and the mean frequen cy of micronuclei per binucleate cell in lymphocytes from cancer patie nts.