Flow cytometry detection of EMPs.

EMPs were labeled using annexin V–FITC or mAbs directed against endothelial-specific molecules (VCAM-1, endoglin, E-selectin) used alone or in combination (3End mAbs) as described in “Materials and methods.” EMPs (gate A) were discriminated by size on an FSC–SSC cytogram. They were further analyzed for fluorescence associated with irrelevant and specific antibodies. Graphs are representative flow cytometry dot plots depicting fluorescence intensity versus side scatter intensity (FL1–SSC) of EMPs counted using 3-μm latex beads (gate B) as an internal standard. The horizontal gate was drawn at a fluorescence intensity above the background level.