Separation of human bone marrow cells in density gradients of polyvinylpyrrolidone coated silica gel (Percoll).

A simple and highly reproducible method is described for separation and density distribution analysis of human bone marrow cells in continuous density gradients of polyvinylpyrrolidone coated silica gel (Percoll). Colony and cluster forming cells in agar separated from the bulk of cells and peaked at densities of 1.063-1.064 g/ml. The enrichment of clonogenic cells was approximately 10 times and recovery varied between 41-321%. The overall recovery of cells was 80% (60-94%). Density distribution analysis of morphologically identifiable cells demonstrated the progressive increase in density with maturation of cells within the granulocytic series: myeloblasts peaked at 1.0624 g/ml, promyelocytes at 1.0734 g/ml, myelocytes at 1.0776 g/ml, metamyelocytes at 1.0799 g/ml and mature neutrophils at 1.0864 g/ml. The eosinophil had the highest density, 1.0904 g/ml, of all cells analyzed. Monocytes and lymphocytes peaked at 1.0661 and 1.0681 g/ml respectively. The light density shift of clonogenic cells of AML and CML reported by other authors was confirmed.