Comparison of 32P-postlabeling and high pressure liquid chromatographic analyses for 7,12-dimethylbenz[a]anthracene–DNA adducts

[3H]7,12-Dimethylbenz[a]anthracene-modified DNA obtained from mouse cells in culture was enzymatically hydrolyzed to nucleoside 3'-phosphates, postlabeled with[32P]phosphate, and the carcinogen-modified nucleoside bis-phosphates were separated by thin layer chromatography. Each adduct spot was eluted, dephosphorylated and the resulting [3H]nucleoside adducts were analyzed by high pressure liquid chromatography so that the structural information available for the liquid chromatographic peaks could be applied to the spots obtained from the postlabeling procedure. After this cross referencing, specific dihydrodiol epoxide-nucleotide adducts can now be monitored by the postlabeling technique.