Gallocyanin-chrome alum counterstaining of Golgi-Kopsch impregnations

A simple technique is described for counterstaining Golgi-Kopsch impregnations. The sections are first stabilized by the method of Geisert and Updyke and then stained in 0.15% gallocyanin and 5% chromium potassium sulfate for 45 minutes at 55-60 C. The sections are then rinsed, dehydrated to 70% ethanol, cleared in terpineol, mounted and coverslipped. This procedure results in a light to medium blue stain of those cells not impregnated by the silver chromate. The major advantages of this procedure over earlier methods are: (1) the counterstain does not fade and (2) since no differentiation is required, many sections may be stained simultaneously.