A Glycine-Hcl-Formalin Fixative for Improved Staining of Neuroglia

The pH of fixatives as well as the components of the fixative mixture exert a displacing action on the isoelectric point of tissue proteins, which influences the intensity of staining. Studies of these effects showed that ammonium nitrate, sulfate or chloride could be substituted successfully for ammonium bromide in Cajal's formalin-ammonium bromide fixative. However, the best results from staining with Rio Hortega's silver carbonate and with Cajal's gold-sublimate methods were obtained after fixation in a mixture consisting of: glycine, 1.05 gm; 12V HCl, 14.8 ml; concentrated formalin, 15 ml and distilled water to make 100 ml.