Detection of DNA adducts by postlabelling with 3H-acetic anhydride.

A method has been developed for detecting 7-alkylguanines which is based on derivatization of hydroxyl and primary amino groups with 3H-acetic anhydride. The derivatization procedure is devised for 7-methylguanine, with examination of reaction kinetics. The method is applied to the detection of the isomeric styrene oxide-guanine adducts; styrene-7,8-oxide is the active metabolite of styrene. The procedure can be used as a postlabelling method for the simultaneous detection of several adducts after selective depurination of 7-alkylguanines from DNA.