Fig. 1. Characterization of endothelial progenitor cells. Out-grown from 14 days, endothelial progenitor cells grew into monolayer with “cobblestone” appearance (A , 100× magnification). Immunofluorescent endothelial progenitor cells were positive for cytoplasmic vascular endothelial growth factor receptor 2, and CD133 (B , 200× magnification, and C , 200× magnification, green fluorescence ). Nuclei were counterstained in blue fluorescence . Fluorescence confocal microscopy (200× magnification) found that the endothelial progenitors of day 7 were positive for uptake of DiI-acLDL (D , red fluorescence ) and for staining of FITC-UEA-1 (E , green fluorescence ). Overlaying D  and E  results in panel F  (yellow fluorescence ).