Peroxidase and gold complexes of lectins for double labeling of surface-binding sites by electron microscopy

Double labeling experiments were performed for visualization of the binding sites of Concanavalin A and anti-AHel (the lectin from Helix pomatia). The anti-AHel was labeled with the colloidal gold whereas the membrane bound Concanavalin A was demonstrated by an affinity technique using horseradish peroxidase. The two markers used could be clearly distinguished electron microscopically. The specificity of the cell surface double labeling was demonstrated in the control experiments. A topological distinct localization of the both lectin-binding sites is evident.