Platelet and fibrin accumulation in laser-induced arteriole and venule injuries in wildtype and untreated FVIII^null mice. Analysis of in situ laser injury in cremaster arterioles and venules. Average platelet accumulation was measured using an Alexa⁶⁴⁷-labeled anti-CD41 Fab fragment (RVU), and fibrin clot accumulation using an Alexa⁴⁸⁸-labeled anti-fibrin antibody (RVU). Studies of wildtype (WT) mice are shown on the top row and FVIII^null mice on the bottom row, with arterioles on the left and venules on the right for both rows. The number of individual injuries and total mice used are noted at the top of each graph. Measurements are in relative value units and held constant throughout these studies.