Cytospin preparations representing morphology of erythroid cells at different stages of the culture. The percentages of erythroid cells at each stage of differentiation were determined microscopically after May-Grünwald-Giemsa (MGG)–stained cytospins. Images were captured with an Olympus BX40 microscope, 40×/0.95 numerical aperture lens, fitted with Olympus Camedia C-3040ZOOM camera, and processed with Adobe Photoshop (Adobe Systems, Mountain View, CA). (A) Proerythroblasts (40%, ) are present on day 5, although lymphocytes () are the most abundant cell type. (B) Basophilic normoblasts (50%, ) are discernible on day 8. (C) Day 11 preparation demonstrates polychromatic erythroblasts (65%, ). (D) Day 15 culture shows late erythroblasts with pycnotic and shrunken nuclei (95%, ).