FIGURE 2.

Rhein sensitizes E. coli to MMS by enhancing the m³C accumulation. A, plate killing assay to show growth of E. coli Gold during exposure to 50 or 75 μm MMS with 100 μg/ml rhein, respectively. The density in the top line is A₆₀₀ 0.005. B, cfu count assay to show resistance of E. coli Gold to MMS in the presence of rhein. The error bars are means ± S.E. (n = 6). **, p < 0.1; ***, p < 0.001. C, growth of E. coli Gold in the presence of MMS and compound BA. D, the quantification of m³C (upper blot) and AlkB protein (lower blot) in E. coli Gold using blot assays. ns, not significant.