A Chlorate-Formaldehyde Modification of the Golgi Method

Pieces of fresh nervous tissue 3–5 mm thick are put into a mixture of: 6% K2Cr2O7, 40 ml; 5% KClO3, 20 ml; 20% chloral hydrate, 30 ml; and concentrated formalin (38% HCHO), 10 ml; allowed to fix 3 days, with a daily change of fluid; transferred to 3% K2Cr2O7 for 3 days, with twice daily changes; then to 1% AgNO3 for 3 days at 20-25° C. Frozen sections are cut, dehydrated, cleared and mounted in Permount with a cover glass. The method gives good results for microglia and oligodendroglia in addition to the usual staining of nerve cells and their processes.