Pretransfusion (labeled or unlabeled) and posttransfusion (control or during inflammation) platelet surface markers stimulated with TRAP as determined by flow cytometry. (A-C) Surface markers were similar for both short- and long-term stored PCs after stimulation with TRAP. (D-I) The line plots show the mean and standard deviations of the percentage of activation and prophagocytic markers over time of transfused PCs up to 48 hours after transfusion. No major differences were found between short- and long-term stored PCs after stimulation with TRAP. At a few time points, CD63 expression was higher in short-term stored PCs (panel E). The line plot displays the mean and standard deviation of surface markers over time. Statistical comparisons were performed at each timepoint using an unpaired t test, alongside a 2-way repeated measures ANOVA to assess changes over time and between conditions. Significance levels are indicated as follows: ∗P < .05; ∗∗P < .01; ∗∗P < .001; ∗∗∗∗P < .0001; NS, not statistically significant.