Evaluation of magnetic alginate beads as a solid support for positive selection of CD34+ cells

Paramagnetic alginate beads with a 10-100 microns size range have been developed. These beads, when activated with chloroacetic anhydride and covalently coupled to avidin (30 micrograms/mg beads), were able to bind biotinylated goat anti-mouse (B-GAM) antibody (Ab). The beads with immobilized antibody were then used as a model system for the capture and non-enzymatic release of CD34+ (KG1a) cells. A maximum of 82% KG1a (average = 65 +/- 16.1%) cell capture, and 57% (average = 51 +/- 5.9%) cell release has been attained using this model system. Optimization of the system in terms of further bead size reduction, and in terms of developing a system to recover released cells with high purity, will make an excellent system for cell capture and nonenzymatic release.