[Morphological observation of erythroid progenitor cell differentiation in vitro]

Iscove's methylcellulose method was adopted and modified for the culture of erythroid progenitor cells isolated from BABL/c mouse bone marrow, and in vitro differentiation of the erythroid cell colonies was observed morphologically. Experimental results indicated: (1) in culture medium with a low concentration of erythropoietin, colonies of different sizes composed of tens to several tens of largely unsynchronized cells were formed from the late erythroid progenitor cells (CFU-E); (2) in culture medium with a high concentration of erythropoietin, the early erythroid progenitor cells (BFU-E) could be stimulated to form larger colonies which consisted of several thousand to ten thousand more highly synchronized cells; and (3) the process of pyknosis and extrusion of nuclei from the late erythroblasts could be readily observed in both the CFU-E and BFU-E colonies.