Detection of DNA Adducts by 32P-Postlabeling and Multifraction Contact-Transfer Thin-Layer Chromatography

³²P-Postlabeling is a sensitive method for detecting DNA adducts.Large bulky adducts, particularly from polycyclic aromatic compounds,are readily detected using this technique. Detection of smallmodifications, such as methylations, has often required specificadditional enrichment procedures prior to ³²P-postlabeling.We report the use of a single analytical procedure that candetect DNA adducts of a wide range of sizes and hydrophobicities(exemplified by adducts produced with methyl methanesulfonate,diepoxybutane, styrene oxide, or benzo[a]- pyrene). This ³²P-postlabeling/thin-layerchromatography procedure is particularly useful when examiningthe potential of novel compounds or their metabolites to formDNA adducts.