Application of histochemical techniques in electron microscopy as applied to high polymers

Abstract

AbstractStaining reactions are necessary to reveal the fine structure of fibrous polymers in electron microscopical investigations. Reactions of heavy metal salts with organic compounds yield different results depending on pretreatment of the fibers, the nature of the heavy metal employed, and the conditions of treatment. In the case of keratin fibers, the structure as revealed by the electron microscope depends mainly on the conditions of treatment. For example, wool, after carboxymethylation, shows a complete reversion in contrast compared with untreated material. It is thus possible to reveal the sulfur‐rich fraction of keratin with a staining reactive which normally reveals the low‐sulfur fraction. The quantitative analysis is, in both cases, in good agreement with the electron‐microscopical results. Further examples of staining reactions are discussed, especially the reactions of keratin and cellulose fibers with silver salts.