Static platelet adhesion to extracellular matrices. Anticoagulated whole blood from CD151^+/+ and CD151^–/– mice was labeled with DiOC₆ (50 μg/mL) and washed platelets were isolated. Labeled platelets/mL (1 × 10⁹ platelets/μL) were then allowed to adhere to collagen-coated (2.5 mg/mL), fibrinogen-coated (100 μg/mL), or bovine VWF–coated (20 μg/mL) coverslips in the presence of botrocetin (1 μg/mL) for 15 to 60 minutes at 37° C. Adherent platelets were fixed at different time points and visualized using fluorescence microscopy. Quantitation of adherent CD151^+/+ and CD151^–/– platelets was determined by analysis of images acquired using × 100 objective. These data represent the mean ± SEM from 3 independent experiments. HPF indicates high power field.