Morphology of erythroblasts from normal donors and patients with DBA. Cytocentrifuge preparations were prepared from day 10 and 14 BFU-E–derived erythroblasts cultured with or without 100 ng/mL SCF. BFU-E–derived erythroblasts from a representative normal donor are shown at day 10 (A, −SCF; B, +SCF ), and day 14 (C, −SCF; D, +SCF ) and from a patient with transfusion-dependent DBA at day 10 (E, −SCF; F, +SCF ) and 14 (G, −SCF; H, +SCF ) of maturation. Preparations made from three additional patients and normal donors showed similar results.