Normal ex vivo thrombus formation and clot retraction of Cyfip1-deficient platelets. (A) Thrombus formation was assessed on collagen at different shear rates. Shown are representative fluorescence pictures of platelets stained with a Dylight-488 anti-GPIX antibody (n = 5, representative for 3 independent experiments). Scale bar, 30 µm. (B) Surface coverage and (C) relative thrombus volume were quantified. (D) Clot formation was observed over time and (E) residual serum volume was measured (n = 3, representative for 2 independent experiments).