The selective affinity of anionic detergents for elastica: a new stain for elastica.

This report concerns the observation that certain anionic detergents have a specific affinity for elastica, and because these anionic detergents precipitate cationic basic dyes in aqueous solution, a rather specific stain for elastica can be obtained. There are many satisfactory methods for the histologic demonstration of elastica, the most popular being: a) acid orcein (Unna), b) Verhoef's, c) Weigert's and d) Gomori's aldehyde-fuchsin stains (1, 2, 3). Though most of these methods have been known for many years their specific histochemistry remains unexplained. Indeed the chemical nature of elastica is, in itself, poorly understood. Recent reports (4, 5, 6, 7, 8) suggest that elastica consists of proteinfibrils which are embedded in amorphous sulfated polysaccharide. Being a complex of protein and mucin, Hall (4) proposes the term elastomucin for elastica. In the light of our incomplete knowledge of the complicated nature of elastic tissue, a general term such as elastica will be retained in this report and will refer to biologic material which is stained by the conventional methods for elastica.