Fig. 2. Lentivirus-enhanced green fluorescent protein (eGFP) label endothelial progenitor cells (EPCs) in vitro  and detection of EPCs in injured lung tissues. EPCs were cultured at day 7 (A , 200× magnification). EPCs were transfected with eGFP (B , 200× magnification, and C , 400× magnification, green fluorescence ). EGFP-label EPCs were detected by immunohistochemistry (D , 400× magnification) or fluorescence microscopy (E  and F , 200× magnification) in injured lung tissues 2 days after EPC infusion. (E ) eGFP-positive EPCs (green fluorescence ). (F ) Control, nuclei-stained with 4′,6-diamidino-2-phenylindole (blue fluorescence ).