Differentiation of Friend erythroleukemic cells in media lacking fetal calf serum

The results presented in this paper provide evidence that the erythroid differentiation induced with n-butyric acid (BA) in F4N Friend cells depends mainly on the ability of different media to support an active cellular proliferation. No significant differences in the percentage of hemoglobin-positive cells were observed when a comparative induction was performed in media, supplemented with either calf or fetal calf serum; the most satisfactory results were obtained in Dulbecco's minimum essential medium (DMEM), lacking fetal calf serum but containing calf serum instead. The great sensitivity of cells to BA in the presence of calf serum allows us to suggest that there is not any component, specific for the fetal calf serum, critically required for the induction of erythroid differentiation in this clone.