Lectin staining of carbohydrates of haemic cells; the cells of normal blood and bone marrow and of the myeloid leukaemias.

Plant proteins and aprotinin (a protein of beef lung), labelled with fluorescein isothiocyanate, were used as histochemical tools for the demonstration of carbohydrates. Sialic acid (or glucuronate) was stained with aprotinin (FLA); galactose was stained with Ricinus communis agglutinin (FL-RCA) and mannose (or glucose) with Concanavalin A (FL-Con-A). Normal human bone marrow and blood were examined as were the cells of patients with acute and chronic myelogenous leukaemia. The plasmalemma, cytoplasm and nuclear membrane of the cells of the normal granulocytic series were stained well with FLA, but the corresponding leukaemic cells fluoresced less intensely. Chromatin was weakly stained in both normal and leukaemic cells. FLA-RCA and FL-Con A stained the plasmalemma, cytoplasm and nuclear membrane weakly, but did not demonstrate chromatin. There was no detectable difference between normal and leukaemic cells. Eosinophil and basophil granules--in contrast to those of the neutrophils--stained well with all three compounds, in both the normal and leukaemic cells. In megakaryocytes and platelets the plasmalemma and cytoplasm were well stained with FLA. The cytoplasm of megakaryocytes and the plasmalemma of platelets stained particularly well with FL-RCA. The cytoplasm of both platelets and megakaryocytes showed up strongly with FL-Con A. In the erythroblastic series all three compounds stained the plasmalemma. The remaining cellular components were weakly stained, except the chromatin; that of the late erythroblasts showed up particularly well with FLA. Lymphocytes, monocytes and reticulin cells of the bone marrow were also stained with all three reagents. Reticulin fibres were stained strongly with FLA and FL-Con-A.