Platelet PDI plays a critical role in platelet accumulation but not initial adhesion and fibrin generation at the site of laser-induced arteriolar wall injury. Intravital microscopy was performed as described in “Materials and methods.” (A) Representative fluorescence images associated with platelets (red) and fibrin (green) are shown over the course of 180 seconds after vascular injury. White arrows show the direction of blood flow. (B-E) The median integrated fluorescence signals of anti-CD42c (F platelet) and anti-fibrin antibodies (F fibrin) were obtained from 28-30 thrombi in 3 WT or 6 CKO mice and is presented as a function of time. Little fluorescence signal was observed by fluorescently labeled control IgG (data not shown). (C,E) The fluorescence signal is shown at 60, 120, and 180 seconds after vascular injury. *P < .05; **P < .01 vs WT mice after Kruskal-Wallis test. (F) After infusion of wtPDI or dmPDI (100 μg), Dylight 649–conjugated rat anti-mouse CD42c and Dylight 488–conjugated anti-polyHis antibodies or mouse IgG1 were infused into PDI CKO mice. The representative images were obtained from 18-20 thrombi in 3 PDI CKO mice per group and are shown as T_max for platelet thrombus formation. (G) The median integrated fluorescence signal of anti-polyHis antibodies (PDI binding) is presented as a function of time.