THE ACTION OF HISTOLOGICAL FIXATIVES ON TISSUE LIPIDS. COMPARISON OF THE ACTION OF SEVERAL FIXATIVES USING PAPER CHROMATOGRAPHY

Abstract

A simple procedure to obtain information on the influence of fixatives on tissue lipids is described. The action of several histological fixatives on tissue lipids was investigated by extraction of the lipids from fixed tissues followed by analysis of the extracts by paper chromatography. Primary fixatives as well as fixative mixtures were investigated. Formaldehyde reacts very fast with phosphatidylethanolamine; other lipids are attacked gradually. The greater part of the lipids become insoluble under influence of dichromate and chromic acid. The still extractable part consists mainly of oxidation products. Osmium tetroxide immobilises most lipids in fresh and in formaldehyde fixed tissues. Mercuric chloride is shown to react with several lipid components, possibly by formation of addition complexes with highly unsaturated fatty acid chains. The fixative mixtures additively display the actions of the individual components; the chemically reactive components tend to dominate the results.