Separation of CD34 positive cells and determination of surface homing antigen.

To study the differences in homing potential between bone marrow cells and umbilical blood cells, CD34 positive cells were obtained from bone marrow (BM) and umbilical blood (UB) by the direct cell separation with domestic immunomagnetic beads. The expression of the two adhesion molecules CD11a/CD18 and CD44 were examined. After separation, CD34 positive cells accounted for 51%-82% of the harvested cells and dye-resistance rate was 82%-88%. The expression of CD11a/CD18 and CD44 on the surfaces of UB cells was 49.6% +/- 10.2% and 37.7% +/- 10.3% respectively. On BM cells they were 50.2% +/- 6.2% and 34% +/- 13.3% respectively. There were no significant differences in the expression of these two molecules. It was concluded that the cell separation method with domestic immunomagnetic beads was effective and the stem cells from UB could serve as an alternative source for transplantation.