An evaluation of the genotoxicity of O-tyrosine, a proposed marker for irradiated food

V79 Chinese hamster cells and Molt-4 human cells have been used to test the cellular and genetic toxicities of o-tyrosine addition at concentrations far in excess of that found after irradiation of chicken to 10 kGy (~1.3 μg/ml). No toxicity, as measured by sister chromatid exchange, micronuclei formation, or reproductive death, was seen in cells exposed to concentrations up to 100 μg/ml o-tyrosine. After 2 d in 200 μg/ml o-tyrosine, Molt-4 cells had a higher percentage of dead cells in the population, but the growth rate and micronuclei formation were not affected.