Effect of Proteolytic Enzymes and Fixation on Metachromasia of Skin Collagen

Abstract

Human skin, obtained at autopsy or operation, was used. Frozen sections were made of unfixed material; some were treated with 5% soln. of crystalline pepsin or trypsin in the unfixed state; others were fixed in either neutral formalin or 80% ethanol. Unfixed skin collagen treated with pepsin became metachromatic. Trypsin did not have this effect. Denatured collagen was rendered metachromatic by both pepsin and trypsin.