General morphology and composition of Tsp1-null platelets. (A) Transmission electron microscopy of murine WT platelets and Tsp1^-/- platelets. The scale bar represents 5 μm. (B) SDS-PAGE under reducing conditions and Western blot analysis of the platelet content in TSP-1, fibrinogen (Fg), and fibronectin (Fn), as indicated. (C) Multimer analysis via agarose gel electrophoresis of von Willebrand factor (VWF) in WT and Tsp1^-/- plasma and platelets, with representative scans of the multimer distribution patterns. AU indicates arbitrary units.