The Use of a Cation Exchange Resin in Decalcification

Decalcification of 2-3 mm. sections of human ribs by 5-40% concentrations of both formic and nitric acid was subjected to a controlled study. The effect of adding 1 g. of phloroglucinol and of 2.5, 5 and 10 g. of the exchange resin (Win-3000) per 100 ml. of decalcifying solution was observed after staining celloidin sections with hematoxylin and Triosin or with Giemsa stain. Electrolytically decalcified material was included for comparison also. The following conclusions were drawn: (1) The addition of resin did not appreciably shorten the decalcification time nor enhance tissue preservation and staining qualities. (2) Formic acid, 20% or less, gave results superior to nitric acid in any concentration and also superior to those obtained after the electrolytic method. (3) The addition of 1% phloroglucinol to formic acid solution improved both preservation and staining. (4) Helly's fluid fixation with all combinations gave uniformly better results than formalin fixation.