Growth of normal and tumour haemopoietic cells on glass coverslips in peritoneal cavity of mice. II. Immunological identification of bone marrow colony-forming cells.

The effect of rabbit anti-mouse brain serum and monospecific antibodies to an antigen of erythroblasts, Ag-Eb, on cells forming haemopoietic colonies on glass coverslips was studied. These colonies developed on the fibroblast-macrophage layer formed on glass coverslips which had been inserted into the peritoneal cavity of mice. when bone marrow cell suspensions were treated with RAMBS and the complement, or with anti-Ag-Eb antibodies plus complement, the CFU-GC colony-forming ability remained unaffected. In the examined cell suspensions, RAMBS inactivated 44% of CFU-S. When bone marrow cell suspensions were treated with anti-Ag-Eb antibodies, the number of immature erythroid cells was reduced to 75%. The CFU-GC are presumed to resemble the committed (unipotent) haemopoietic progenitor cells.