vWF binding to immobilized TSP. (A) Results of a microtiter dish binding assay. vWF bound to immobilized TSP in a concentration-dependent manner (TSP, ▪). Nonspecific binding to BSA-coated wells (no TSP,□) and lack of binding in the presence of EDTA (circles) are also shown. (B) Inhibition of binding by anti-TSP antiserum. vWF (2.5 μg/mL) binding to immobilized TSP in the presence of increasing amounts of anti-TSP antiserum (circles) or control serum (squares) is indicated.