DETECTION OF DNA LESIONS INDUCED BY CHEMICAL MUTAGENS BY THE SINGLE-CELL GEL-ELECTROPHORESIS (COMET) ASSAY .1. RELATIONSHIP BETWEEN THE ONSET OF DNA-DAMAGE AND THE CHARACTERISTICS OF MUTAGENS

We evaluated the relationship between the onset of DNA damage and the characteristics of 5 model chemical mutagens with the single-cell gel electrophoresis (SCG) assay using L5178Y mouse lymphoma cells. We trea ted the cells with each chemical for 3 h and sampled them 0, 21, and 4 5 h after treatment. DNA damage induced by UV mimetic mutagens MMS and MNU, and X-ray mimetic mutagen BLM was observed just after treatment, crosslinking agent MMC-induced DNA damage was detected 21 h after tre atment, and 6-MP as an inhibitor of DNA synthesis did not induce DNA d amage at any sampling time. These results suggest that the SCG assay d etects DNA lesions just after treatment with UV and X-ray mimetic muta gens, but needs a waiting period after treatment with crosslinking age nts. (C) 1997 Elsevier Science B.V.