Figure 2. Comparison of the bacterial bioburden (colony-forming units per milliliter [CFU/ml]) and two indices of polymerase chain reaction (PCR) analysis for each case. A: Bacterial bioburden versus cPCR-d (the corrected difference in PCR intensity, defined as the difference in the mean intensities of a PCR band and its background). B: Bacterial bioburden versus cPCR-r (the corrected ratio of the PCR intensity, defined as the ratio of the mean intensities of a PCR band and its background). a.u., arbitrary unit.