Sample Aging Profoundly Reduces Monocyte Responses in Human Whole Blood Cultures

Figure 3

Cytokine-producing cells in whole blood cultures (average plus SD). The whole blood of 5 donors was stimulated for 3 hours with LPS (a) or PMA/ionomycin (b) in the presence of brefeldin A to block cytokine secretion. The percentage of positive cells for intracellular cytokines was quantified for T-cells (continuous lines) and monocytes (dashed lines). The -axis indicates the sample age (time span between blood collection and start incubation). The blood was stored at room temperature. T-cells and monocytes remained negative for IFNγ staining after LPS stimulation.

(a)

(b)