Isolation of CD34 + Cells from Umbilical Cord Blood

Abstract

CD34⁺ cells were isolated from umbilical cord blood using AIS polystyrene devices containing covalently immobilized soybean agglutinin (SBA) and the CD34 monoclonal antibody ICH3. In the procedure, mononuclear cells were prepared using Ficoll-Hypaque density gradients and loaded into an AIS MicroCELLector™ SBA to bind many differentiated cell types and to enrich for CD34⁺ cells. Subsequently, the nonadherent SBA-negative cells were loaded into an AIS MicroCELLector™ CD34 to capture the cord blood stem cells. After incubation the CD34⁺-adherent cells were removed by agitation. This purification scheme was performed on 28 cord blood samples where the mean volume collected was 116 ml. On average, 4 x 10⁸ mononuclear cells were harvested after the density gradient, with 20% of those cells being SBA-negative. A mean of 1.9 x 10⁶ cells or 0.5% of the starting mononuclear cells were recovered in the final CD34⁺ population. CFU-GM, BFU-E, and CFU-GEMM were enriched 47- to 48-fold in the final fraction with 75% recovery of early CFU-GEMM progenitors throughout the entire process. The results establish the feasibility of using this technology for the isolation of CD34⁺ cells from cord blood. (The paper covering this material appears in the Proceedings of the International Workshop on Cord Blood Transplantation, which appears in this issue. See page 275.)