Fig. 4

UCB-NHSC phenotype is different when grown on uncoated TCP versus ECM. a Culture on extracellular matrix (ECM) for 1 month promoted the growth of UCB-NHSCs better than uncoated tissue culture plastic (TCP). Phase contrast micrographs of cells cultured on the two culture surfaces are shown at two different magnifications. b Flow cytometric analysis of UCB-NHSCs grown on uncoated TCP or ECM. Cells grown on ECM expressed SSEA-4, an ES cell marker, as well as other MSC markers (CD29, CD105, and CD146), but not HSC markers (CD34 and CD45). Cells stained with non-specific antibody (isotype IgG) were used as negative controls (gray peaks). The initial population of MNCs from UCB was analyzed without culture and used for comparative purposes. c A growth curve of UCB-NHSCs maintained on ECM (P5). Population doubling time during the first 5 days of culture was determined as described in the Methods. Cell counts are expressed as the mean ± SD using triplicates