Visualization of surface antigens on yeast protoplasts by gold or ferritin markers

Surface antigens of Saccharomyces cerevisiae protoplast were visualized immunocytochemically with protein A-gold or ferritin conjugated antibodies. Ferritin particles were densely distributed at the surface of yeast protoplast after treatment with rabbit anti-protoplast serum and ferritin conjugated antibody against rabbit IgM. Control experiments demonstrated that the binding of these ferritin markers was specific for surface antigens. The composition of these surface antigens, however, remain to be investigated.