A reliable Golgi-Kopsch modification

A reliable Golgi-Kopsch variant is described. Tissue is fixed with 1% paraformaldehyde, 1% glutaraldehyde in 0.1 M phosphate buffer, pH 7.2. Tissue slabs (2.5--4 thick) are immersed for 5--7 days in a solution containing 3.5 g potassium dichromate, 15 g sucrose, 1.65 ml formaldehyde in 100 ml distilled water, washed briefly in 0.75% silver nitrate, and immersed in 0.75% silver nitrate for 2--3 days. Procedures for cutting, counterstaining, and handling sections are described.