Platelet adhesion on surfaces coated with vWF at different densities. Glass slides were coated with different concentrations of vWF, and densities of vWF adsorbed on the glass surfaces were calculated from the relationship shown in Fig 1. Platelet adhesion was measured under shear rates of 200 (▪), 800 (▴), and 3,200/s (•). The mean ± SEM of 2 series of experiments were plotted, except for the values without bars that indicate values from single experiments and the values of 4.35 ng/mm2 that represent the average of five experiments.