Development Of An Assay to Determine The Amount Of Binding Between DNA And The Carcinogen (+)-Anti-Benzo (a) Pyrene Diol Eopxide

Abstract

A method for determining the number of carcinogenic molecules bound (adducted) to a DNA sequence was studied. Samples of purified plasmid DNA were exposed to increasing concentrations of the carcinogenic chemical benzo(a)pyrene diol epoxide (BPDE). Treated plasmids then served as the template in a Polymerase Chain Reaction (PCR). Desired test regions of the plasmid were selectively amplified. Samples from the PCR were then electrophoresed to study the number of successful copies produced by the PCR and the size and density of the bands. DNA replication levels decreased proportionately as BPDE exposure concentrations increased. The results suggest that the number of BPDE adducts in a DNA sequence increases as exposure levels increase. This correlation can be used to develop a means of accurately quantifying the number of adducts in a given DNA sequence.