Quantification of the number of rolling platelets over VWF and FKN coimmobilized with VWF. Washed platelets were preincubated with modulators as described in Figure 3 and perfused over VWF and FKN coimmobilized with VWF. The number of rolling platelets was quantified after removing firmly adherent platelets by image processing. (A-B) Perfusion at a wall shear rate of 150 s⁻¹ (A) and 600 s⁻¹ (B). Shown is the percentage of platelets rolling on FKN coimmobilized with VWF, and the number of platelets rolling on VWF alone (C-D) was set to 100% for each treatment (dotted line). *P < .05, **P < .01, ***P < .001 in one sample t test versus 100%, which represents the number of platelets rolling on VWF only surfaces. (C-D) The absolute number of platelets rolling on VWF-coated surface at the wall shear rate of 150 s⁻¹ (C) and 600 s⁻¹ (D). The results are the mean ± SEM of at least 4 independent experiments with blood from different donors.