FIG. 5.

The effect of variable time of rifampin and 2-AP treatment on chromosome degradation in dam-mutant cells. (A) dam culture treated with 2-AP for 1 h at 37°C was centrifuged, resuspended, and incubated in LB containing rifampin. At different times, samples were precipitated with methanol and analyzed as described in the text. (B) 2-AP was added to a dam culture and, after various times, 0.4 ml of culture was centrifuged for 2 min at room temperature and the pellet resuspended in LB containing rifampin, followed by incubation for 90 min at 37°C before methanol treatment. Finally, cells were analyzed as described in the text. DAPI int (integral) is the area signal of the pulses produced at the detector as the cell passes through the measurement region.