Effect of change in the temperature at which blood was maintained before testing on the CD11bSurface. Fresh, heparinized whole blood was collected from healthy people by phlebotomy and immediately incubated at 0°C, 25°C, or 37°C for 30 min (incubation period 1) followed immediately by incubation at 37°C for 30 min (incubation period 2) and then CD11bSurface was measured as described in the Methods. For each sample, the CD11bSurface at the end of incubation period 2 was subtracted from the CD11bSurface at the end of incubation period 1, divided by the CD11bSurface at the end of incubation period 1 and multiplied by 100 percent. Positive values indicate an increase in CD11bSurface after incubation period 2 compared to after incubation period 1. Bars represent the mean ± SD for n = 3 per condition. Comparisons were made by ANOVA with Dunnett's test; *** = P<0.001.