Fluorescent confocal imaging and immunostaining of FeCl3-injured mouse carotid arteries. Photomicrographs show fluorescent confocal imaging and immunostaining of mouse carotid arteries after vascular injury. EPCs were labeled with an intracellular fluorescence marker (DiL) 1 hour prior to injection in WT (Panel D) and P-sel−/− (Panel G) mice and assessed by confocal fluorescence on cryostat cross-sections. Panel A represent the injured arteries from non-labeled PBMC-treated mice used as negative control. The corresponding Differential Interference Contrast (D.I.C) of the identical sections of each carotid is shown on the right (panels B, E & H). (Scale bar = 50 μm). Anti-CD34 immunostaining of the injured arteries in EPC-treated mice show that CD34 positive cells were uniformly distributed within the thrombus and along the vessel wall in WT - but poorly distributed in P-sel−/− mice confirming the recruitment of EPCs to the luminal aspect of arterial thrombi in vivo (arrows in F and I). The cells in C are CD34 negative. The images are representative of at least 4 independent experiments.