Fig. 4.

(A) Configuration for SMFS measurements. A mAb (CD41 or PAC-1) modified AFM tip is positioned above a live platelet (containing membrane embedded αIIbβ3 receptors). (B) Typical force distance cycle for MRFS experiments. An unbinding event with an unbinding length of ∼50 nm and a rupture force of ∼60 pN is shown. In the blocking experiment (inset) no specific unbinding event occurred. (C) Binding probability of CD41 and the PAC1 mAb to αIIbβ3 receptors in the membrane of live platelets on glass plotted against time.