ANALYSIS OF TAMOXIFEN-INDUCED DNA-ADDUCTS BY P-32 POSTLABELING ASSAY USING DIFFERENT CHROMATOGRAPHIC TECHNIQUES

DNA isolated from livers of rats receiving tamoxifen was analysed by t he P-32-postlabelling method. The postlabelled DNA hydrolysis mixture was analysed both by reversed-phase HPLC with P-32 on-line detection a nd by TLC on polyethyleneimine plates followed by autoradiography. Usi ng the HPLC method, five well separated adduct peaks could be detected , while by the TLC method, two groups of adduct spots were observed. T he detection limit of the TLC assay was lower (0.5 adducts/10(10) nucl eotides) than that of the HPLC assay (3 adducts/10(10) nucleotides). T hus, the TLC assay is more sensitive but also more laborious. The adva ntages of the HPLC assay were, in addition to better resolution, the e ase of quantification and operation.