Immunomagnetic selection of CD34+ cells from fresh peripheral blood mononuclear cell preparations using two different separation techniques.

Immunomagnetic separation using anti-CD34 monoclonal antibodies and paramagnetic microspheres has been used to enrich hematopoietic stem cells from human bone marrow, whole cord blood, or mobilized peripheral blood mononuclear cell collections. The aim of the present study was to compare the efficacy of two different CD34+ cell selection techniques in enriching CD34+ cells from mobilized fresh peripheral blood mononuclear cells. Using the magnetic cell sorter (MACS), the final product purity was 74.1% CD34+ cells (starting population 2.3% +/- 3.3%) with a 60.3% CD34+ cell yield. Using Dynabeads and subsequent chymopapain incubation for releasing the target cells from the beads (Isolex system), the released cells contained 83.3% CD34+ cells (starting population 1.2% +/- 0.7%) with a 43.4% yield. These results indicate that CD34+ cells can be isolated with high purity from fresh leukapheresis products using both immunomagnetic techniques.