We attempted to develop a purification method for cell cycle-dormant murine multipotential progenitors that is simple and has a high recovery. Multilineage colony formation from mice that had been treated with 150 mg/kg 5-fluorouracil was assayed in cultures containing interleukin-3, interleukin-6, and erythropoietin. The cells with density 1.0631-1.0770 g/cm3 were approximately 40-fold enriched for multipotential progenitors. Negative immunomagnetic selection with a panel of lineage-specific monoclonal antibodies including anti-B220, anti-Gr-1, anti-Mac-1, anti-L3T4, and anti-Lyt-2 resulted in a cumulative 150-fold enrichment. When the density-separated and lineage-negative cells were further enriched by fluorescence-activated cell sorting with monoclonal antibody D7 (anti-Ly-6A/E), total enrichment averaged 800-fold and recovery was 17%. The method described here provides a relatively simple technique for the isolation of the multipotential progenitors and should be useful for the studies of regulation of hemopoiesis.