[A ruthenium red-osmium tetroxide section staining method (author's transl)]

We suggest a method for the section staining of polyanions by means of ruthenium red and osmium tetroxide. A 5 min incubation in diluted ruthenium red-OsO4 solution pH = 7.4 of ultrathin Durcupan-sections previously treated with sodium methoxide results in the opaque stining of mast cell granules, cartilage proteoglycans, and various epithelial mucosubstances.