Radiation sensitivities of escherichia coli to gamma-rays under deep frozen conditions

Radiation damage on living organisms is induced by direct and indirect effects. Gamma-irradiation to living organisms in aqueous media is greatly effected by hydroxyl radicals produced by the radiolysis of water. However, radiation effect under frozen conditions is not clear. In order to know the effect of free radicals on microorganisms in aqueous media, gamma-irradiation was carried out under deep frozen conditions, because the movement of hydroxyl radicals is expected to be restricted under these conditions. Irradiation of E. coli was also carried out in the presence of glycerol, a kind of radical scavenger. (J.P.N.)