AbstractTraditional methods for the staining of nerve fibers and endings in paraffin sections are tricky and lengthy.1 2Silver nitrate technics often produce precipitates on the sections and. there is a tendency for sections to be lost due to floating free from the slides. Existing copper protargol procedures tend to stain some connective tissues (especially after 10% formalin fixation),3require the use of counterstains, and are of long duration. However, the use of urea4in the staining solution, a slight lowering of pH and the raising of the temperature makes the use of copper protargol practical on a day to day basis by overcoming these difficulties.