RT-PCR screen for endogenous reference genes in presurgical, SIRS, and sepsis discovery set granulocytes. Sixteen known reference genes assembled in the TaqMan Array Human Endogenous Control Panel were tested in randomly selected discovery set samples (presurgical, n = 5; SIRS, n = 5; sepsis, n = 6). Threshold cycle (Ct) values are represented as group averages. Data points are connected by lines to aid visual comparisons between groups. The overall mean coefficient of variation (CV) for these determinations was 4.3%. CV values were < 7.2% except for determinations of 18S in SIRS (22.3%) and sepsis (14.4%).