Fig. 5. Colony formation of E14.5 Dlk^- and Dlk⁺ cells. Dlk^- and Dlk⁺ cells were isolated from E14.5 fetal liver by AutoMACS and cultured at a density of 1000 and 50 cells/cm², respectively, on type IV collagen-coated 6-well plates in the presence of 20 ng/ml of HGF and EGF. The number of cells in each colony was counted after 5 days of culture. Data shown here are numbers of colonies formed from 500 Dlk^- (black bar) and Dlk⁺ (white bar) cells. 24±3% of E14.5 Dlk⁺ cells formed various sizes of colony after 5 days of culture. Among those colony-forming Dlk⁺ cells, 10% formed large colonies containing over 100 cells.