Near-optimal conditions for the in vitro culture of hemopoietic progenitor cells in bone marrow from the rat.

In vitro techniques for the culture of hemopoietic stem cells and committed hemopoietic progenitor cells in rat bone marrow have not been adequately described in the literature. In the present investigations, and using commercially available hemopoietic cytokines and growth factors, the conditions required to perform long-term bone marrow culture (LTBMC) using rat femoral bone marrow were studied, in conjunction with the colony-forming unit cell assay (CFU-C), to quantify the number of progenitor cells. CFU-C production by LTBMCs, set up using Iscove's modified Dulbecco's medium supplemented with fetal calf serum and horse serum, ceased after week 2 of culture. However, the duration of CFU-C production was significantly increased by supplementing LTBMCs with the cytokine recombinant mouse stem cell factor or recombinant rat stem cell factor.