Surface differentiation of hemopoietic cells demonstrated ultrastructurally with cationized ferritin.

The ultrastructural cationized ferritin (CF) technique was employed as a probe of the surface binding characteristics of the various cell types present in normal human bone marrow. The number of CF particles per micron length of cell surface were counted and data subjected to statistical analysis. All cells of the bone marrow exhibited CF reactivity. The extent of labeling was cell specific and could be related to the stage of maturation of the cells in a given lineage. In the neutrophilic series, myeloblasts showed moderate labeling while promyelocytes and myelocytes revealed only minimal binding; CF binding increased sequentially in metamyelocytes, band and segmented neutrophils. Eosinophils and eosinophilic myelocytes showed similar membrane differnetiation patterns while basophils exhibited stronger CF labeling that other granulocytic cells. Lymphocytes were strongly reactive while monocytes and their precursors were moderately labeled with CF. Surface reactivity of developing nucleated erythrocytic cells was similar to that of the lymphocytes. Surface labeling from the proerythroblasts to early normoblasts stage was identical, CF binding increased in the late normoblasts stage and then decreased in the reticulocyte and mature erythrocyte stages. The extent of surface CF reactivity of the marrow cells was markedly different from that obtained with Thorotrast and colloidal iron. Thorotrast and colloidal iron stained the surface of all marrow cell intensely but failed to yield distinctive surface labeling patterns for the differing cell population in bone marrow.