FIG. 3.
Northern hybridization analysis of total RNA of B. fragilis strain 638R (wild type). RNA was isolated from cells grown to mid-logarithmic phase in BHIS and then treated as described in the text: 500 μM diamide (D), 50 μM hydrogen peroxide (P), exposed to air (O), or untreated (An). (A) Autoradiographs of blots hybridized to radiolabeled probes containing the entire open reading frame of each trx gene as indicated. The approximate sizes of the transcripts are shown. The apparent bands (*) at about 1.5 and 2.5 kb are a commonly observed compression artifact caused by the 16S and 23S rRNAs. (B) Fold increase of transcript levels under each condition compared to the anaerobic control based on densitometric values. Black bars, 500 μM diamide; white bars, 50 μM H2O2; hatched bars, aerobic exposure.