Dose-response analysis of thrombin- and collagen-induced phosphatidylserine exposure in human platelets.

<p>Phosphatidylserine exposure by human washed platelets was quantified by measurement of fluorescent annexin V binding in flow cytometry. <b>A</b>. Representative flow cytometry histograms of annexin V binding to non-stimulated resting (control) platelets or to platelets incubated with various concentration of thrombin or collagen, as indicated above the charts. The histogram obtained for control platelets was superimposed in grey to that of stimulated platelets for better visualization of fluorescence shifts. <b>B</b>. Bar graph representing the mean annexin V binding to non-treated control platelets (CTL) and to thrombin- or collagen-stimulated platelets. Results are expressed as percent relative to the mean fluorescence intensity of CTL platelets. n = 4 different blood donors, # indicates a significant statistical difference (p<0.05) from CTL platelets.