BIOMONITORING AND P-32 POSTLABELING ANALYSIS OF DNA-ADDUCTS

The carcinogenic activity of many genotoxic chemicals is initiated by the covalent binding of these compounds or their metabolites to DNA. Measurement of DNA adducts in men is useful for the evaluation of biologically effective exposure dose of environmental carcinogens and mutagenes. P-32-postlabeling assay, one of the most sensitive method for DNA adduct detection at present, is readily applicable to monitoring changes in human DNA. It is highly sensitive (1 adduct/10(9)-10(10) nucleotides), the assay can be performed with small quantities of DNA (1-10 mug) and it is applicable to adducts with a wide range of chemical structures. The article reviews the P-32-postlabeling procedures involving a stepwise sequence of biochemical reactions. The other methods like immunoassays, scanning synchronous fluorescence spectroscopy, HPLC and GS/MS are mentioned. Special attention is paid to the application of P-32-postlabeling method and ELISA-immunoassay for detection of exposure-related DNA adducts in human studies. The use of DNA from surrogate cells like while blood cells, which are a readily obtainable source for human DNA is discussed. Endogenous DNA adducts (called I-compounds), which can be detected using the high sensitive P-32-postlabeling procedure are also mentioned.