Assessment of platelet functionality following separation and fluorescent labeling.

(A-C) Log forward/log side light scatter FACS analysis of CFDA-labeled platelets demonstrates a distinct population of unstimulated platelets (A). Platelet aggregation demonstrates a shift of the platelet population toward higher granularity and size in response to weak agonist ADP (100 μM; panel B) and low concentrations of human thrombin (0.05 U/mL; panel C). (D) Aggregometry of CFDA-labeled platelets revealed biphasic platelet aggregation in response to 2 U/mL human thrombin.