Sickle and normal RBC adherence to immobilized TSP and vWF. Glass microscope slides, which form the base of the parallel plate flow chamber, were coated with either TSP (50 μg/mL) or vWF (20 or 100 μg/mL) and then blocked with 1% BSA for 60 minutes. A washed suspension of RBC (1% Hct in serum free medium) was perfused over the immobilized proteins for 10 minutes, followed by a 10-minute rinse with cell free medium at a shear stress of 1 dyne/cm². Results demonstrate that sickle RBC adhered preferentially to immobilized TSP in comparison to vWF and BSA (nonspecific control). Similar levels of sickle RBC adhesion were observed for recombinant vWF (wt vWF ) and plasma-derived vWF (pvWF ) at coating concentrations of 20 μg/mL and 100 μg/mL. Data are shown for wt vWF at 20 μg/mL and for pvWF at 100 μg/mL. Error bars are standard error of mean (SEM).