Abstract: | A new E. coli DNA polymerase I directed nick translation assay was used for measuring 7,12-dimethylbenz[a]anthracene-induced in situ DNA damage and repair in mouse mammary epithelial cells in monolayer culture. The nick translation assay was capable of detecting a DMBA-dose dependent significant increase of DNA damage, and the same assay also allowed monitoring of the DNA repair activity provoked by DMBA treatment of the epithelial cells. This relatively simple method thus provides a rapid assay for carcinogen-induced in situ DNA damage and repair in an epithelial cell tumorigenic system. |