Granulocyte-macrophage colony formation in vitro using human non-phagocytic bone marrow cells.

A technique employing silica particles was used to remove cells producing endogenous colony-stimulating factor (CSF) to allow measurement of the level of colony-forming units in culture (CFU-C) in human bone marrow cells. In comparison with the glass-adherence technique, this new approach resulted in a more complete degree of removal of CSF-producing cells and formation of more colonies. This method seems to be useful for performing an accurate assay of exogenous CSF.