Abstract: | Photoreactivation (PR) was measured after inactivation by far (254 nm), middle (300-315 nm) and near (315-400 nm) UV radiation of Paramecium caudatum and 8 strains of Escherichia coli differing in PR and dark repair capability. PR volume was high and practically the same after irradiation by far and middle UV, but PR was not observed in near UV-inactivated cells of all the strains. It is proposed that pyrimidine dimers are not significant in near UV lethal lesions in cells, as near UV-irradiated phages (T7 and lambdacI 857) are not photoreactivated in undamaged host bacterial cells. |