Figure 4. Ratiometric pre-rRNA analysis M. bovis BCG cells in serum.

Cells were incubated separately in filtered and unfiltered human serum at 37°C for 30 days. The serum-incubated cells were then resuspended in pre-warmed 7H9 broth and samples were taken after 0,1, 2, 4, and 24 hours. P:G ratios were calculated as in Figure 2. Values are means and SDs of nine ratiometric permutations from three technical replicates of each sample type. From a five-point gDNA standard curve, qPCR efficiency was calculated as 1.001. A separate experiment with H37Ra yielded similar results (Figure S2).