Erythropoiesis in vitro: daily determination and quantitation of cell types and expression of surface proteins.

The 6 upper panels show daily percentage of a given cell type among all cells in culture calculated in a blinded fashion from cytospin preparations; blast indicates undifferentiated blast; prepro, preproerythroblasts; pro, proerythroblasts; baso, basophilic normoblasts; poly, polychromatic normoblasts; ortho, orthochromatic normoblasts. Stained cytospins performed on days 1, 5, 7, 9, 11, and 13 are shown on the right. The bottom panel demonstrates surface phenotype of cells in culture stained for glycophorin A (GPA), transferrin receptor (CD71), and CD34.