Tracing of intravenously or iBM-injected PKH26-labeled CB CD34⁺ cells.

(A) Representative FACS analysis of PKH26-labeled cells. Column-enriched CB CD34⁺ cells (i) were stained with PKH26 (ii) and were transplanted into irradiated NOD/SCID mice by intravenous (iii) or iBM (iv) injection. Five minutes later, PKH26⁺cells circulating into peripheral blood stream were identified by flow cytometry. The number at each panel represents the percentage of PKH26 bright cells detected. (B) Comparison of the percentage of PKH26⁺ cells detected in PB and BM from intravenous (filled bars; ▪) or iBM (open bars; ■) injected NOD/SCID mice at 5 minutes and 20 hours after transplantation. BM cells were aspirated from left (noninjected side) tibia. Fifty thousand events were acquired to calculate the proportion of PKH26⁺ cells. Data shown are the mean ± SD values of 3 independent experiments (n = 5). The number above each bar represents the mean percentage of PKH26⁺ cells.