Immunocytochemistry of bone marrow and cord blood. (A-C) Patient A-II-1. Bone marrow, monoclonal antibody; and APAAP detection. (A) Pronormoblast. (B) Normoblasts. (C) Negative control, omitting primary antibody. (D-E) Normal bone marrow, showing normoblasts. Polyclonal antibody, ABC detection. (F-G) Patient A-III-1, cord blood. Polyclonal antibody, ABC detection. Most red cells are nonimmunoreactive. In panel F, 2 normoblasts (NO) are seen with stomatin immunoreactivity at the nucleus. One nonimmunoreactive lymphocyte (NIRL) is seen. In panel G, normoblasts extruding the nucleus can be seen (Nen). Counterstained with hematoxylin. Bar represents 10 μm.