Detection of human exposure to carcinogens by measurement of alkyl-DNA adducts using immunoaffinity clean-up in combination with gas chromatography-mass spectrometry and other methods of quantitation.

A brief overview is given of recent developments from our laboratory in the use of immunoaffinity clean-up in the determination of alkyl-DNA adducts. Compound- and group-specific antibodies have been prepared against 7-alkylguanines and 3-alkyladenines. The antibodies were attached to solid supports to make immunoaffinity columns which could then be used to selectively purify either single adducts or groups of adducts prior to quantitation by various methods. In the case of methyl adducts quantitation was achieved by ELISA (3-methyl-adenine, using a monoclonal antibody) and HPLC-electrochemical detection (7-methylguanine). For groups of adducts, quantitation of the individual compounds was effected by gas chromatography-mass spectrometry (3-alkyladenines, using deuterated analogues of each adduct as an internal standard) and HPLC-fluorescence detection (7-alkylguanines). In all of these cases efficient purification of adducts from urine or DNA hydrolysates could be easily carried out. Using these techniques human exposure to alkylating agents in tobacco smoke and from cancer chemotherapy has been studied.