Improved method of enrichment for immature myeloid cells from normal human bone marrow.

A method of enrichment for immature myeloid cells from normal human bone marrow has been described. The method is based on 4 consecutive steps: 1. Density cut centrifugation. After centrifugation all cells above the pellet were collected. This suspension contained 93% of the originally present myeloblasts and promyelocytes. The majority of normoblasts and granulocytes was found in the pellet. 2. Nylon wool filtration. This procedure was performed to remove the majority (87%) of the monocytes. Recovery of myeloblasts and promyelocytes after filtration was 74%. 3. Centrifugation on a continuous density gradient. This procedure resulted in an additional purification of the myeloblasts and promyelocytes within a specific fraction. By centrifugation the concentration of myeloblasts and promyelocytes was increased from 19% to 38%. 4. Velocity sedimentation at 1 g. This technique produced a 82% pure immature myeloid cell suspension, comprising 57% myeloblasts and promyelocytes. All figures are the mean of 10 experiments.