Characterization of Developing Adult Mammalian Erythroid Cells Separated by Velocity Sedimentation

Abstract

S ummary . By virtue of their different sedimentation rates at unit gravity, different classes of erythroblast have been separated from the bone marrow of the anaemic rabbit. Each class of erythroblast has been characterized by morphological and biochemical criteria. The classes thus characterized form a series of cell types leading from the large immature erythroblast to the marrow reticulocyte. The fractionation procedure permits complete separation between erythroblasts which synthesize RNA and those which are no longer active in RNA synthesis.