Akt3 knockout delays formation of stable thrombi. (A) Washed mouse platelets (200 μL, 3 × 10⁸/mL) were loaded onto slides coated with 50 μg/mL collagen and a cone and plate rheometer was used to introduce shear stress (800 seconds⁻¹) to the platelets. Mepacrine, a fluourescent dye was added to the platelets before applying shear stress for 5 minutes. Slides were rinsed in a container with PBS to wash out nonstably adherent platelets. Slides were viewed with a Leica DMI RB fluorescence microscope (Leica Microsystems). (B) Quantitation of panel A using t test (P < .001). (C) FeCl_3-induced carotid artery injury was performed, and time to occlusive thrombosis was recorded as described under “In vivo thrombosis.” The occlusion time of each mouse is shown as squares (Akt3^−/−, n = 10) and triangles (Akt3^+/+, n = 10). The bars represent the median occlusion time. Statistical analysis was performed using the Mann-Whitney test to evaluate the differences in median occlusion time (P = .0007).