Table 1. Effect of CR on CB-derived CD34+ cells after 7 days in culture.

Human CD34⁺ cells from UCB were transplanted directly (uncultured) or cultured for 7 d (CR or vehicle) before transplantation. A serial dilution of uncultured or CR-cultured cells (based on the number of cells present before culture) was injected into NOD-SCID hosts. The percentage of human CD45⁺ cells in peripheral blood at 12 weeks was measured and >1% was considered positive for engraftment. The frequency of SCID repopulating cells (SRCs) calculated with L-Calc software was not significantly different between uncultured and cells cultured in CR (p = 0.7088).