Figure 1

Flow cytometry analysis of CD3, CD14, CD15, CD19, and CD41 expression. Platelet-rich plasma (PRP) was prepared by centrifugating peripheral blood from healthy donors and collecting in the upper phase. Leukocytes were also recovered at the interphase between the PRP and the red cells. The contaminating red cells in the leukocyte suspension were removed by lysis. Platelets (A,D) and leukocytes (C,D) were stained for lineage markers (CD3⁺ T cells, CD14⁺ monocytes, CD15⁺ neutrophils, CD19⁺ B cells and CD41+ platelets). Fluorescence analysis was gated on the R5 region for PRP (A,B) and on R6 region of the cytogram for leukocytes (C,D). The presence of mononuclear cells in PRP preparation, although significant, was clearly lower than in leukocyte preparation. The expression of CD14 on platelets from PRP was compared to that of washed platelets (E) after gating on CD41-positive cells in the R5 region of the cytogram (data are expressed as percentage of CD expression ± SD; n = 10 experiments). Cytograms shown (A,C) are representative of 10 independent experiments. *P < 0.05 (Wilcoxon paired test; platelets PRP vs. washed platelet suspension).