Short-term quantitative in vitro cytotoxicity assay involving an S-9 activating system.
Mouse 3T3 fibroblasts grown in 96-well microtiter plates are used for a test which incorporates an S-9 mixed function oxidase system into a neutral red viability assay for the assessment of the acute cytotoxicity of xenobiotics in vitro. This sensitive, quantitative, semi-automated assay was suitable for the rapid screening of a broad spectrum of substances, including pharmaceuticals, carcinogens, and anti-neoplastic agents. The test was applicable to the analysis of toxic ranges, for the detection of biotransformability of parent compounds and for the evaluation of the cytotoxic effects of chemotherapeutic agents.