Ristocetin- and botrocetin-induced binding of recombinant vWF to platelets. Conditioned media from transfected COS-7 cells labeled with ¹²⁵I–AvW-1 were incubated with formalin-fixed platelets in the presence of ristocetin (1.2 mg/mL, Ristocetin, shaded bars), botrocetin (2 μg/mL, Botrocetin, hatched bars), or control buffer (Control, open bars) as described in Materials and Methods. After pelleting platelets and associated bound vWF, bound and unbound¹²⁵I–AvW-1 was detected by gamma counting, and percent bound ¹²⁵I–AvW-1 calculated as described in Materials and Methods. The percent ¹²⁵I–AvW-1 bound from normal pooled plasma (NP, n = 3), wt recombinant vWF (WT, n = 4), recombinant vWF containing the mutation from Family A (F606I, n = 5), Family B (I662F, n = 5), type 2M^Milwaukee-1 vWD (▵629-639, n = 2) or conditioned medium from mock-transfected cells (Mock, n = 4) are plotted as the mean ± SD.