A Modification of the Glees Silver Impregnation for Normal and Degenerating Nervous Tissue

Abstract

A modification of the Glees method for silver impregnation of normal and degenerating nervous tissue is described. It offen geat reliability, evenness of impregnation and since it can be used on batches of slides, is also suitable for histology dass material. The results are illustrated. The procedure for paraffin sections of formalin-Iixed material is as follows: dewaxed and celloidin coated sections are left in 20% silver nitrate solution for 2 hr or until light brown. They are then treated successively in Nauta reducing agent (400 ml distilled water, 45 ml 96% ethanol, 13.5 ml 10% formalin, 13.5 ml 1% acetic acid)—10 min, ammoniacal 5% silver nitrate solution in 80% ethanol (5 g AgNO₈ are dissolved in 100 ml 80% ethanol and 25% ammonia solution is added drop by drop until the precipitate clears)—15 min, rinse in absolute ethanol—10 sec. Reduce in two changes of reducing solution (400 ml 10% formalin, 50 ml 96% ethanol, 20 d 1% aretic acid)—10 min, rinse in tap water, fix in 5% sodium thiosulphate—3 min, rinse in tap water, dehydrate sections, remove celloidin, and mount in DePeX. The ammoniacal silver nitrate solution must be freshly prepared before use. The importance and use of the various additives to the solutions are discussed and suggestions are made to enable users to alter the character of the impregnation to suit special purposes.