Chromatography of erythroblasts on immobilized transferrin.

Affinity chromatography with immobilized transferrin has been used to effect a partial purification of erythroblasts and reticulocytes from bone marrow. Human transferrin was covalently attached to Sepharose CL-2B, Bio-Gel A-1.5, A-0.5, P-20, P-6, P-4, and P-2, and Sephadex G-75. Nucleated erythroid cells bound to the greatest degree to the polyacrylamide P-6 bead, whereas reticulocytes had the greatest affinity for the Sepharose CL-2B bead. The polyacrylamide P-6 bead has a greater density of surface groups than the Sepharose bead, and this correlates to the greater density of transferrin receptors on erythroblasts. The beads were used in a column which contained a central stirring bar with multiple crosspieces. The stirrer provided a method to uniformly agitate the beads to facilitate elution of the cells bound to the matrix. Approximately 1-2 x 10(8) bone marrow cells could be applied to a 25-ml matrix bed. This procedure resulted in a considerable resolution of cell types and gave a high yield of reticulocytes and erythroblasts from rat and rabbit bone marrow.