A New Method for a Mutagenicity Test Using Spectrophotometry

Abstract

A new method for a mutagenicity test with spectrophotometry is presented in this paper. The mutagenic activity was examined by monitoring the growth situation of the Salmonella typhimurium TA98 strain. It was found that this strain could mutate and regain its growth capability owing to the impact of dimethyl sulfate; thus, metabolites of the strain caused the culture system to exhibit turbidness. The optimum experimental conditions were obtained. The effect of the dose of the mutagen on the absorbance was also studied. The result showed that there was a good linear relationship between the absorbance and the dose of the mutagen over the range of 2.5 - 20 µg/ml; the regression equation was A = 1.27×10^-3 + 0.0134C, where A is the absorbance and C in µg/ml is the concentration of the mutagen. This method requires no immobilization or preincubation of the microorganism, and can be directly applied to mutagen detection. It is thus rapid and convenient.