Fundamental Studies on Colony Formation of Erythroid Progenitor Cells

Abstract

Fundamental studies on CFU-E colony formation were done using bone marrow cells of mice by the methylcellulose culture method. 1) The number of CFU-E colonies reached a peak after 48 hours of incubation. 2) A linear relationship was observed between the number of CFU-E colonies and the number of inoculated bone marrow cells. 3) The number of CFU-E colonies increased dependently on the concentration of erythropoietin (Epo) and reached almost a plateau above 0.25 U/ml. There was little difference in the CFU-E colony forming activity of the two sources of Epo (one partially purified from human urine at our laboratory and the other obtained from Connaught Laboratories Ltd. as Step Ⅲ derived from plasma of anemic sheep). 4) There was little difference in the number of marrow CFU-E of two strains of mice (ddY and BDF₁). 5) The best conditions in the concentration of culture medium were 10-30% in FCS, 0.5-1.0% in BSA, 10^-4 M in 2-mercaptoethanol, respectively. These observations are thought to be useful for the development of studies on CFU-E.