Fig. 2.

Effects of HEM on the ex vivo expansion of human HSCs from different sources. Human CD34⁺ cells purified from fresh UCB, cryopreserved CB, and mPB were cultured with HEM to day 4 or day 9. Total cell (a) and CD34⁺ cell (b) expansion was calculated as fold increase (after/before expansion) in cell counts on each day (days 0, 4, and 9). Data are shown as mean ± SD, n = 10. c Types of CFU colonies formed from the hematopoietic stem/progenitor cells before/after expansion. Equal numbers of unexpanded human CD34⁺ cells and 9-day HEM-expanded CD34⁺ cells (1 × 10⁴ per dish) were assayed as described in Methods. Data are shown as mean ± SD, n = 4. Pairwise comparisons (unexpanded vs expanded) were performed for each type of colony using Student’s t test (p > 0.05 for all pairs). d–f Representative flow analysis for multi-immunophenotyping of the expanded cells on day 0, day 4, and day9. Gates of CD34⁺ CD38⁻, CD90⁺, CD45RA⁻, and CD49f⁺ cell populations were set based on the fluorescence minus one (FMO) of each cell surface marker antibody. CD38⁻, CD90⁺, CD45RA⁻, and CD49f⁺ were analyzed in CD34⁺ cell population