THE CHEMICAL SPECIFICITY OF THE SCHULTZ TEST FOR STEROIDS

Abstract

The colours given by a number of pure steroids under various strongly acid conditions have been studied both in the test tube and in model sections prepared in various ways. Aqueous sulphuric acid solutions containing ferric ions were found to give an intense blue-green colour with steroids closely related chemically to testosterone, and colours in the pink-mauve range with certain other steroids such as the oestrogens and pregnenolone. The blue-green colour has two sharp absorption bands in the red which make possible the conclusive identification of the testosterone group of compounds. A new modification of the Schultz reaction has therefore been devised: frozen sections of formalin-fixed material are mounted on slides, blotted dry, treated with a drop of 80% aqueous sulphuric acid containing 0.5% iron alum and the resulting colours observed. This procedure has several advantages over previous modifications: there is no charring and very little cytological distortion; the colours are stable for many hours, and their chemical specificity is more clearly defined. Cholesterol itself gives no colour, but preliminary oxidation (e.g. by preincubation in iron alum) leads to the formation of the typical blue-green colour. Various aspects of this new histochemical modification of the Schultz reaction are discussed.