Culture of EPCs from human peripheral blood. (A) Two methods for isolating and culturing EPCs from human peripheral blood. Yellow cells represent nonadherent cells and red cells represent adherent cells. FN indicates fibronectin. (B) Representative phase-contrast photomicrograph of a CFU-EC colony (day 5) cultured from adult peripheral blood MNCs by method A. Similar colonies were observed from 29 other adult peripheral and 10 cord blood donors. Scale bar represents 500 μm. (C) Representative phase-contrast photo-micrograph of an ECFC colony (day 19) cultured from adult peripheral blood MNCs by method B. Similar colonies were observed from 29 other adult peripheral and 10 cord blood donors. Arrows indicate colony boundary and scale bar represents 500 μm.