Ultrastructure and cytochemistry of bone marrow granulocytes in culture

Leukocytes from human bone marrow, grown in clonal cell culture with methylcellulose medium, were characterized ultrastructurally and cytochemically, utilizing techniques for demonstrating peroxidase, acid phosphatase, dialyzed iron reactive mucosubstance, antimonate reactive cation and Concanavalin A surface receptors. Neutrophils and eosinophils were identified in culture specimens and in many respects resembled those seen in direct marrow specimens. Cultured neutrophils, however, did not develop secondary (specific) granules and the crystalloids of eosinophil granules appeared abnormal. The strong reaction of neutrophil primary granules with antimonate and dialyzed iron afforded differentiation from unreactive monocyte-macrophage granules and thus distinguished these cell types in culture. Basophils were observed in morphologic preparations and their granules stained most intensely for acid mucosubstance with the dialyzed iron method.