Micro-Ames assay

Assays that detect reverse mutation are most popular, largely because of the development of the Salmonella/micro-some assay by Bruce Ames and his co-workers.10 13 All five of the strains that sure currently recommended95 contain point mutations that prevent the biosynthesis of histidine. Unless histidine is provided in the growth medium, the bacteria cannot grow. However, if a new mutation occurs at the site of the original mutation and "reverses" its effect, growth without histidine can take place. 

McCann, J. and Ames, B.N., Detection of carcinogens as mutagens in the Salmonella/micro-some test assay of 300 chemicals discussion, Proc. Natl. Acad. Sci. USA, 73, 950, 1976. 

As with the Salmonella reversion assay, this shortterm test is conducted both without (— PMS) and with metabolic activation produced by addition of post-mitochondrial supernatant containing rat liver enzymes ( + PMS). These terms are equivalent to — S9 and + S9 in the Ames reversion assay we use the latter designation for both types of bacterial assays. A more sensitive micro-forward mutation bioassay using this TM677 strain to determine the mutagenicity of indoor air particles, including ETS and wood smoke, is described by Lewtas et al. (1987). 

No genotoxic activity of a polysaccharide fraction of zedoary was observed in the Ames test for mutagenicity with or without metabolic activation with S9. No clastogenic activity of the same polysaccharide fraction was observed in micro-nucleus or chromosomal aberration assays performed using Chinese hamster lung fibroblast cells with or without metabolic activation (Kim et al. 2000). 

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