Ultrastructural studies of mouse leucocytes showing surface binding of peroxidase-conjugated lectins.

Examination in the electron microscope of mouse spleen cells treated with conjugates of wheatgerm agglutinin and horseradish peroxidase has shown the surface of myeloid cells to be heavily stained. Resting lymphocytes were unstained but became positive after stimulation by phytohaemagglutinin or concanavalin A, suggesting a relationship between the presence of this surface component and the functional state of the cell and providing a further point of similarity between myeloid and lymphoblastoid cells. The conjugates have also been useful in tracing the fate of surface carbohydrates during phagocytosis.