Evaluation of a DNA polymerase-deficient mutant of E. coli for the rapid detection of carcinogens.

Differential growth inhibition of two E. coli cultures was evaluated as a rapid screening technique for chemical carcinogens. Of the carcinogens tested, only "direct acting" carcinogens produced positive results. Furthermore, this test is not a quantitative assay in that neither was a dose--response relationship seen nor did potent carcinogens necessarily show a greater response than weaker carcinogens.