FIG. 6.
UV resistance of cells containing the ΔrecBCD::Plac-red allele. AB1157 (wild type; circles), KM21(ΔrecBCD; triangles), and KM22 (ΔrecBCD::Plac-red; squares) were grown to 2 × 108 cells/ml, spun down, resuspended in minimal medium, and kept on ice. Cells were diluted in minimal medium, spread on LB plates, exposed to the indicated doses of UV, and grown overnight in the dark. KM22 was grown and plated in the presence (closed squares) and absence (open squares) of 1 mM IPTG. Unirradiated plates were used to determine the total number of cells plated.