Definition of flow cytometric erythroblast subsets. (A) Flow cytometric analysis of freshly isolated bone marrow cells labeled with antibodies against Ter119 and CD71. Dead cells were excluded with 7-AAD. The left panel shows all viable bone marrow cells. Ter119^high cells are further analyzed with respect to their forward scatter (FSC) in the right panel. (B) Cytospin preparations of cells sorted from the ProEs and Ery.A, B, and C subsets shown in panel A are stained for hemoglobin with diaminobenzidine and counterstained with Giemsa. Scale bar represents 5 μm.