IMMUNOAFFINITY CONCENTRATION OF HUMAN LUNG DNA-ADDUCTS USING AN ANTI-BENZO[A]PYRENE-DIOL-EPOXIDE-DNA ANTIBODY - ANALYSIS BY P-32 POSTLABELING OR ELISA

DNA, isolated from 15 human lung autopsy samples, was examined for the presence of polycyclic aromatic hydrocarbon (PAH) DNA adducts. Using the nuclease P1 modification of the P-32-postlabelling technique, between 1 and 12 adducts/10(8) nucleotides were detected prior to immunoconcentration. Autoradiograms from most of the samples revealed a diagonal smear of radioactivity consistent with complex mixture (cigarette smoking) DNA damage. The DNA samples were digested to oligonucleotides, made single-stranded and subsequently applied to immunoaffinity columns containing immobilised anti-benzo[a]pyrene (B(a)P)-7,8-diol-9,10-epoxide (BPDE) DNA polyclonal rabbit antibody. The material remaining bound to the column, in addition to that passing through, was analysed using both ELISA and P-32-postlabelling techniques. Column-bound adducts comprised between 0% and 78% of any particular sample. Immunoconcentration, followed by P-32-postlabelling of the material which had been bound to the column, revealed the presence of a number of discrete adduct spots in autoradiograms of the more heavily adducted samples. Sample DNA not retained by the columns was also analysed; the chromatographic pattern obtained was a dense zone of radioactive material migrating from the origin. This evidence suggests that the composition of PAH-DNA adducts found in human lung samples exhibits wide inter-individual variation.