Interaction of platelets with immobilized monoclonal antibodies 6F1 and 12F1. (A) Whole blood containing 75 μM PPACK as anticoagulant, 200 μg/mL mepacrine to make platelets fluorescent, and unstimulated platelets was perfused over glass surface coated with antibodies as indicated at a flow shear rate of 1500 s^–1. (B) The graph represents the number of platelets adhered on each surface during the time of perfusion. (C) Conditions as described in panel A, but the flow was interrupted for one minute to allow platelets to interact with the antibody-coated surface. The adhered platelets were visualized after the flow resumed at 1500 s^–1. The images represent 4 separate experiments using blood from different donors.