To confirm and characterize the adherent fibroblast like progenitors in human umbilical cord blood, we isolated mononuclear cells from human umbilical cord blood by Ficoll Hypaque. Two main morphologically different kinds of cells were formed by culturing the cells in collagen coated 24 well plastic dishes and flasks. One type was the adherent fibroblast like cells, while the other was loosely adherent clonally expanded round cells. Our experiments demonstrate that the adherent fibroblast like cells possess multilineage potential, including the ability to differentiate into endothelial like cells and to express the mesenchymal cell marker.
