The ability to detect low levels of carcinogen DNA adducts in the tissues of people environmentally exposed to chemical carcinogens is invaluable to epidemiological studies of the incidence of cancer in selective populations. A number of selective methodologies have been developed to quantitate carcinogen DNA adducts. The Randerath 32P-postlabelling technique provides a fingerprint analysis of only polycyclic aromatic hydrocarbon type DNA adducts. However, the 32P- postlabelling method has been adapted in the present study to enable the detection of small alkylation type carcinogen DNA adducts. The detection and quantitation of 06-MeGua adducts in DNA has been shown, by the use of standards, to be accurate as low as one adduct in at least 1,000,000 guanine residues. The presence of unidentified 32P labeled spots has also been observed from the analysis of DNA from cells treated with acrolein and DNA treated with fecapentaene.