Relative amounts of lacZ and lacY mRNA species after antisense PNA treatment. Levels of specific mRNAs were determined using real time PCR with 16S rRNA as an internal control. Mean delta Ct values (target-rRNA) were compared across concentrations of anti-lacZ and anti-lacY PNAs using unpaired t-tests assuming equal variance among groups. Significance was set at p < 0.05 and error bars reflect standard deviation. (A) Samples from cells treated with 0, 200 and 400 nM concentrations of anti-lacZ PNA. (B) Samples from cells treated with 0, 100 and 200 nM concentrations of anti-lacY PNA.