Ablation of Vlk in platelet lineage reduces arterial thrombosis without affecting bleeding times. (A-D) Cremaster arteriole injury was induced by laser ablation in Vlk-cKO mice and Vlk^f/f littermate control mice. Platelet and fibrin accumulation at the site of injury was detected for 180 seconds with DyLight 647–labeled platelet-specific anti-CD42b antibody (0.1 μg/g body weight) and DyLight 488–labeled anti-fibrin antibody (59D8, 0.5 μg/g body weight), respectively. (A) Representative images from a single thrombus evaluated for the appearance of fluorescence signals associated with platelet accumulation (red) and fibrin deposition (green) at indicated time points postinjury (lookup tables at right of images). Median integrated platelet (red) (B) and fibrin (green) (C) fluorescent intensities after laser-induced injury were calculated for all thrombi in Vlk^f/f (n = 3; 39 thrombi, darker color) and Vlk-cKO (n = 3; 52 thrombi, lighter color) mice. (D) Area under the curve (AUC) for platelet and fibrin fluorescent intensities was calculated for all individual thrombi. Error bars represent the median with 95% confidence intervals. (E) Time to bleeding cessation (seconds) in Vlk^f/f (n = 6), and Vlk-cKO (n = 7) mice (unpaired Student t test, P = .6567).