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 small modifications, such as methylations, has often required specific additional enrichment procedures prior to 32P-postlabeling. We report the use of a single analytical procedure that can detect 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-layer chromatography procedure is particularly useful when examining the potential of novel compounds or their metabolites to form DNA adducts.