Aggregation of αIIbβ3-inhibited platelets under flow conditions induced by rFVIIa. Citrated whole blood was incubated with dRGDW (200 μM) in absence (A) or presence (B) of rFVIIa (2 μg/mL) for 5 minutes at 37°C. After addition of calcium chloride (5 mM), the blood was immediately perfused over a coverslip coated with collagen type III at a shear rate of 300 s^–1 for 5 minutes at 37°C using a single-pass perfusion chamber. After perfusion, coverslips were fixed and stained with May-Grünwald/Giemsa and examined by light microscopy (original magnification × 400). Representative images of 3 independent experiments are shown.