Chlorate-Osmic-Formalin Method for Staining Degenerating Myelin

Abstract
A former chance observation that formalin added to a chlorate-osmic staining mixture appeared to stabilize and enhance the differential staining of degenerating myelin was investigated. An arbitrary formula was developed: 1% KClO3, 60 cc.; 1% OsO4, 20 cc.; glacial acetic acid, 1 cc.; and formalin, 12 cc. (all aqueous solutions) which gave clear backgrounds and well stained degeneration. Brain and spinal cord were stained in this 7 to 10 days after formalin fixation for 2 days. The possible relationship of a staining mixture buffered with regard to oxidation-reduction and its staining effects is discussed.