Figure 3

Comparison of colorimetric and clonogenic assays for radiation-sensitive phenotype of E. coli reference strains. Mutant strains listed in Table 1 were compared with the isogenic parental control strain (SR749, WT) for recovery from radiation treatment. (A) X-radiation, 250 Gy. (B) UV-radiation, 100 J m^-2. All data points are means from triplicate experiments. Standard deviations (horizontal bars displaying variation in absorbance values and vertical bars displaying variation in surviving fraction values) are shown. The gray-shaded boxes represent the mean ± 2 sem for the WT strain. Any strain data points that fall outside of the gray-shaded boxes are significantly different (Kruskal-Wallis one way ANOVA on Ranks, P <0.05) in their absorbance and surviving fraction values from the WT strain.