Embedding of Myelinated Nerve Tissue in Water-Soluble Resorcinol-Formaldehyde Resins for Light and Electron Microscopy

Abstract

Two resorcinol-formaldehyde resins (Reform I and II) were tried as embeddins media for light and electron microscopy of transversely sliced peripheral and central myeli-nated nerve tissue. Both resins penetrated the specimens efficiently. Semithin sections of the osmicated specimens could be examined unstained or after staining with toluidine blue. Thm sections of Reform I-embedded white matter showed adequate contrast after staining with lead or potassium permanganate. This was also the case with peripheral nerve specimens but in addition satisfactory resolution of detail was obtained by en bloc staining with uranyl acetate before embedding. The Reform II resin showed less convenient staining properties. Both resins allowed the retention of a large proportion of cholesterol in the specimens.