Inhibition of platelet spreading by incorporation of UN7.79. (A) Confocal images of washed platelets allowed to spread on Fg for 45 minutes and stained for F-actin. Untreated platelets (control), platelets treated with DMSO alone (DMSO), and platelets incorporated with a control IgG (cIgG) spread fully. Platelets loaded with UN7.79 showed long filopodia. Original magnification, × 600. (B) Quantitation of the number of fully spread platelets in panel A. (C) Dose-dependent inhibition of the number of fully spread platelets by UN7.79 incorporation. (D) Corresponding dose-dependent increase of the number of spiky platelets by UN7.79 incorporation. Error bars indicate mean ± SEM of at least 3 independent experiments.