FIG. 5.
RT-PCR analysis of M. tuberculosis trx transcripts under various growth regimens. (A) Cultures of M. tuberculosis H37Rv were grown aerobically to mid-exponential phase (optical density at 600 nm, ∼0.9) and treated individually with the indicated oxidants, each at a concentration of 2 mM, for 2 h. Total RNA was isolated from grown cultures, and RT-PCR was performed with primers specific for the indicated trx transcripts. Total RNA extracted from a nontreated culture was used as a control. A primer pair specific to the sigA transcript was used as an internal control. (B) Control experiment showing that the trxAMtb gene is amplified using M. tuberculosis genomic DNA (GD).