FIG. 2.

Hybridization of the Northern blots prepared from RNAs extracted from E. coli E1 to E6 and probed with either the ampC or the 16S rRNA probe. The strains were cultured until exponential phase. At this point (lane −), a 10-ml aliquot was removed and RNA was extracted. Rifampin (0.2 mg/ml) was added, a 10-ml aliquot was withdrawn immediately (lane 0), and RNA was extracted. Additional aliquots were removed after 2, 4, 6, and 8 min, and RNA was extracted. Panels: A, RNA from E1 probed with the ampC probe; B, RNA from E2 probed with the ampC probe; C, RNA from E3 probed with the ampC probe; D, RNA from E4 probed with the ampC probe; E, RNA from E5 probed with the ampC probe; F, RNA from E6 probed with 16S rRNA probe.