Improvements In The Paraffin Method

Abstract

Dilute hydrofluoric acid alone and in conjunction with glycerin and ethyl alcohol was employed successfully to soften various types of refractory plant materials embedded in paraffin. Serial sections were cut at 6-8 μ and no appreciable deleterious effects on cell walls, cell contents, or staining procedures occurred. “Tannins” and “phlobaphene compounds” can be removed from tissues softened by this method by treating the sections for 12-48 hours with an aqueous solution of chromic acid, potassium bichromate and glacial acetic acid prepared according to the formula given by Johansen (1940).