Surface phenotype of CD47^-/- platelets. (A) Expression of CD62P in CD47^+/+ (○) or CD47^-/- (⬡) platelets incubated in the presence or absence of thrombin for 10 minutes. Data are means ± SEMs for 4 mice in each group. (B) Expression of CD61 in freshly isolated CD47^+/+ or CD47^-/- platelets. Data are means ± SEMs for 3 mice in each group. (C) Expression of phosphatidylserine in CD47^+/+ (○) or CD47^-/- (⬡) platelets aged in PRP for 0 to 40 hours at 37°C. Data are means ± SEMs for 3 mice in each group.