Figure 2.
SOS induction of the sfiA-lacZ reporter construct. An overnight culture of LT1610 was diluted 1/500 into LB, distributed among five flasks, placed at 37° in a shaking water bath, and grown to an OD600 of 0.1. Mitomycin C was then added (t = 0) to the following concentrations (μg/ml): open circles, no drug; filled circles, 3 × 10−3; open squares, 1 × 10−2; filled triangles, 0.1; and filled squares, 1.0. Time points were taken every 30 min during growth and β-galactosidase activity in each sample was determined according to Miller (32), and plotted on the y-axis; time of exposure to Mitomycin C is plotted on the x-axis.