Silver impregnation techniques have been used for the demonstration of the complex carbohydrates in electron microscopy. However, the silver stains were believed to be technically sensitive and time consumming to perform. Currently, due to the need to more specifically evaluate immune complex for localization in certain renal diseases, a simplified procedure in conjunction with the use of the microwave has been developed and applied to renal and other biopsies. The procedure is as follows:
Preparation of silver methenamine solution:
1. 15ml graduated, clear polystyrene centrifuge tube (Falcon, No. 2099) was rinsed once with distilled water.
2. 3% hexamethylene tetramine (methenamine) was added into the centrifuge tube to the 6ml mark.
3. 3% silver nitrate was added slowly to the methenamine to the 7ml mark while agitating. (Solution will instantly turn milky in color and then clear rapidly by mixing. No precipitate should be formed).
4. 2% sodium borate was added to the solution to the 8ml mark, mixed and centrifuged before use.