Platelet functions. (A-C) Fluorescence-activated cell sorter flow analysis of the (A) GPIb-IX-V complex (anti-CD42a), (B) αIIbβ3 complex (anti-CD41a), and (C) P-selectin (anti-CD62P) on control (C) and patient (II-2) platelets before (basal state) and after activation by thrombin receptor agonist peptide (activated state). Histograms present geometric mean fluorescence intensity (geometric MFI). (D) Typical traces representative of normalized (to basal level) fluorescence intensity of Oregon green 488 BAPTA1-AM (representative of the cytosolic Ca²⁺ concentration) recorded using Accury flow cytometer. Platelets from the control (black line) and from the patient (dotted line) were treated, in the absence of calcium (EGTA, 100 µM), with thrombin (THR, 50 or 100 mU/mL) and Ca²⁺ (CaCl₂, 300 µM). (E-G) Platelet spreading. (E) Platelets were adhered on fibrinogen or von Willebrand factor substrates and stained with both Alexa Fluor488-labeled phalloidin and Alexa Fluor594-labeled DNAse I. (F) Platelet surface area and (G) ratio of F-actin to G-actin were measured by ImageJ version 1.42k.