Endothelial progenitor cell characterization. Endothelial progenitor cells (EPCs) were cultured for five days. (a) From left to right, Panel 1: acetylated LDL uptake by adherent spindle-shaped EPCs, FITC-conjugated lectin UEA-1 binding to the surface of EPCs, and double-positive stained EPCs for acetylated LDL uptake and lectin binding. Panel 2: Immunofluorescence detection of the CD34 antigen (red), and KDR (green) on the EPC surface. Panel 3: Immunofluorescence detection of eNOS in a single non-stained EPC (green). Panel 4: Immunofluorescence detection of the CD34 antigen on the EPC surface (red), and eNOS (green). The EPC nuclei were stained with the blue fluorescent DNA dye DRAQ5™. Scale bare 50 μm. (b) A representative colony of EPCs with a central core of round cells that is surrounded by elongated spindle-shaped cells. Scale bare 100 μm.