Platelet agglutination by botrocetin. PRP were stirred and botrocetin was added at a final concentration of 10 (A), 4 (B), or 1 μg/mL (C). Agglutination was measured as the change in light transmission. +/+, wild-type platelets; −/−, GPV-deficient platelets. This experiment was replicated 3 times.