Cloning of human erythroid progenitors (BFU-E) in the absence of fetal bovine serum.

We describe culture conditions which enabled us to clone early human erythroid progenitors (BFU-E) in the absence of fetal bovine serum (FBS). Our medium, which is chemically fully defined, supports proliferation and differentiation of erythroid progenitors comparable to that in FBS-supplemented cultures. Furthermore, it allows cloning of BFU-E from all human haemopoietic tissues (adult marrow, embryonic liver and yolk sac) and adult or perinatal blood. This system should facilitate the investigation of human erythroid differentiation in vitro (e.g. cell-cell interaction, mechanism of action of haemopoietins and inhibitors, regulation of Hb synthesis) as well as the mechanisms underlying myeloproliferative disorders. As an example, we have found that recombinant Ep shows, in this culture system, the same dose response as Ep from conventional sources.