Fig. 3

Large numbers of colony-forming cells can be recovered from cultures of TCP-non-adherent UCB-NHSCs by growth on ECM. Non-adherent (Non-ad.) UCB-NHSCs were collected from uncoated tissue culture plastic (TCP) or extracellular matrix (ECM) after 72 h of culture and then reseeded onto ECM plates. To visualize cell attachment to the ECM (after 24 h of culture), non-adherent cells were removed by washing with PBS and the remaining adherent cells stained with hematoxylin and eosin (H and E) (a, b). For colony-forming unit fibroblast (CFU-F) assay, the reseeded cells were cultured for 1 month on ECM, and then fixed and stained with crystal violet (c, d). Scale bar = 100 μm. e Number of UCB-NHSCs, previously non-adherent to uncoated TCP or ECM, collected after a second culture (rescued) on ECM for 24 h. *p < 0.05