In vivo hemostatic effect of FVIII K1813A in HA mice by a tail clip assay. HA mice were infused with PBS, 1 and 2 μg/kg FVIII K1813A, 2 μg/kg K1818A, 2 μg/kg K1813A/K1818A, or 2 and 4 μg/kg WT. Five minutes after infusion, the terminal 5 mm of the tail was amputated, and shed blood was collected for 40 minutes. Each point represents a mouse. The short horizontal lines in each graph indicate the average values. A one-way ANOVA with Dunnett multiple comparison test was used to determine significance relative to HA mice PBS controls. A Student t test was used to compare between each group. ANOVA, analysis of variance; NS, not significant; PBS, phosphate buffered saline.