Defined, serum-free culture conditions for the GM-micro-clonogenic assay using agar-capillaries.

Culture conditions were determined and optimised for the serum-free growth of granulocyte-macrophage (GM) colonies, derived from mouse bone marrow cells, in agar-containing glass capillaries. The standard medium is DMEM/F-12 (1:1) mixture containing per ml: 10 mg BSA, 35 micrograms transferrin, 20 micrograms soybean lipids and 5 micrograms insulin. In contrast to previous attempts by others, GM-colony yield in serum-free medium was found to be equal to that in serum-containing medium (around 25 colonies/capillary) and to correlate satisfactorily with the cell density at seeding.--The role of polyamine oxidases in cell-proliferation experiments could be studied by this microclonogenic assay without interference from any type of serum.