Characterization of the transfusion product. (A) Morphologic appearance of cells within the transfusion product. (i) Day-7 cells possessed an agranular cytoplasm. The nuclei of the cells had an open chromatin pattern and prominent nucleoli. (ii) Day-9 cells were smaller with compact and relatively smaller nuclei. (iii) Erythroid islands characterized by normoblasts surrounding a macrophage were observed in day-9 cultures. Giemsa-Wright staining (×1000 magnification). (B-C) Phenotypic analyses of the transfusion product: FACS analyses of the cells after days 7 and 9 of incubation was performed by immunostaining with various mAbs to lineage-specific markers including CD36, CD71, GPA, CD14, CD15, CD19, and chemokine receptor marker CXCR4. One of 4 representative experiments is shown.