Efficiencies of DNA Inactivation and Mutation Induction by Tritiated glycerol in Bacterial Systems

Abstract

When spores of Bccillus subtilis were treated in a frozen state with tritiated glycerol of different concentrations (up to 160µCi/mI), efficiencies of killing and mutation induction per absorption dose were higher in solutions of lower tritium concentrations where low dose-rate β-irradiations were performed. Similarly when transforming DNA of Bacillus subtilis was kept with tritiated glycerol solution of concentrations ranging 0.05–500 µCi/ml at 4°C, efficiency of inactivation of the arginine marker increased strikingly by lowering the tritium concentration. On the other hand, the RBE of DNA-strand scissions of colicin El plasmids exposed to tritiated glycerol of a relatively high concentration (680 µCi/ml) was found to be approximately 1, when compared at the same absorption dose of gamma-irradiation (36 kR/hr) from a 137Cs source. © 1981, Journal of Radiation Research Editorial Committee. All rights reserved.