Intranuclear and cytoplasmic hemoglobin in human erythroblasts during maturation. Electron microscopic immunocytochemistry.

Changes in the hemoglobin level in human bone marrow erythroblasts associated with cell maturation were studied by the electron microscopic immunocytochemical technique using protein A-gold. Intense reaction of gold to hemoglobin was observed diffusely in the cytoplasm, but the reaction was weak in the Golgi zone. No reaction was observed in mitochondria or granules. Cytoplasmic hemoglobin was noted in basophilic erythroblasts and increased with maturation. Hemoglobin was also noted in the nucleus, especially in the euchromatin, though in smaller amounts than in the cytoplasm. Since intranuclear hemoglobin tended to increase in the euchromatin but to decrease in the heterochromatin with erythroblast maturation, the ratio of the amount of hemoglobin in the euchromatin to that in the heterochromatin increased with maturation.