Separation of leukemic and nonleukemic subpopulations of spleen cells from mice with myeloid leukemia.

Centrifugal elutriation has been adapted for use in obtaining highly enriched populations of leukemic myeloblasts and normal appearing lymphocytes from RFM/UN mice with myeloid leukemia. The myeloblasts were functionally intact as evidenced by their high cloning efficiency in vitro and malignant potential in vivo. The lymphocyte-enriched subpopulation had a low thymidine labeling index, and cloning efficiency in vitro, and was only marginally malignant in vivo indicating minimal contamination by leukemic myeloblasts. In preterminal leukemic mice the proportion of cycling leukemic cells remained high with a labeling index of 30-50%.