Interaction of flowing platelets with immobilized VWF-A1/12F1 and VWF-A1/6F1. Whole blood was perfused over surface coated with the VWF-A1 (150 μg/mL) mixed with 6F1, 12F1, or mouse IgG (200 μg/mL). After 2-minute perfusion, the coverslips were washed with TBS and several frames of attached platelets were recorded. The photomicrographs represent 3 separated assays.