A testing strategy to evaluate the mutagenic activity of industrial chemicals in cultured mammalian cells

Based on the published guidelines of regulatory agencies and the latest scientific findings, an experimental strategy for the routine testing of the mutagenic activity of industrial chemicals in mammalian cells in vitro is designed. The strategy includes three individual experiments: (1) a range-finding experiment for cytotoxicity to determine the appropriate doses to be used in subsequent mutagenicity testing; (2) mutagenicity testing at limited doses with different concentrations of Aroclor 1254-induced rat liver homogenate (S9); and (3) a more extensive dose-response experiment using an S9 concentration determined to be optimum in mutagenicity. Besides satisfying the guidelines of regulatory agencies, this strategy should yield data that allow sound scientific judgment on the mutagenicity of the chemicals tested.