Comparison of the frequency of SRCs in pre- and postcultured CD34+ CB cells by limiting dilution assay
No. CD34+ cells transplanted . | Engraftment with precultured cells . | Engraftment with postcultured cells . |
|---|---|---|
| 100 000 | 5/5 | 5/5 |
| 50 000 | 7/9 | 6/9 |
| 10 000 | 5/10 | 4/10 |
| 5 000 | 0/5 | 0/5 |
No. CD34+ cells transplanted . | Engraftment with precultured cells . | Engraftment with postcultured cells . |
|---|---|---|
| 100 000 | 5/5 | 5/5 |
| 50 000 | 7/9 | 6/9 |
| 10 000 | 5/10 | 4/10 |
| 5 000 | 0/5 | 0/5 |
The graded number of pre- and postcultured CD34+ CB cells were transplanted into irradiated NOD/SCID mice (n = 58) intravenously. At 10 weeks after transplantation, human cell engraftment in mice was determined by flow cytometric analysis. The detection of human cells was also confirmed by PCR of the human chromosome 17–specific α-satellite primers (data not shown). SRC frequencies were calculated using Poisson statistics and the method of maximum likelihood with the assistance of L-Calc software (StemCell Technologies). Engraftment values indicate number of engrafted mice/number of transplantations.