Fig. 3

Repopulation of sublethally irradiated mice with expanded human CD34⁺ cells. a SRC assay. CD34⁺ cells freshly purified from UCB (Day 0) (10³, 6 × 10³, 10 × 10³ starting cells) or their progeny expanded with HUVECs + h5GF plus PBS or hD1R were transplanted into sublethally irradiated NOD/SCID mice. The peripheral blood cells of the recipients were analyzed by FACS 12 weeks post transplantation. The number of transplanted cells was plotted against the percentage of mice without engraftment to determine the frequency of repopulating units (n = 30). b, c The cells in (a) were transfused into sublethally irradiated NOD-SCID mice. In the 10 × 10³ cells group, the peripheral blood cells of the recipients were analyzed by FACS 12 weeks post transplantation. The percentages of engrafted human CD45⁺ were compared (b) (n = 10). c Representative FACS analysis of hCD45⁺ cell engraftment in (b). d Human CD45⁺ cell engraftment 12 weeks after the secondary transplantation for primary recipient mice in the 10 × 10³ cells group. Horizontal bars represented mean levels of hCD45⁺ cell engraftment in BM. (n = 10). Bars = mean ± SD. *P < 0.05