- Deparaffinize and hydrate sections to dH20. Wash 3x 3 min. in dH20.
- Place sections in 50 ml 10% silver nitrate in dark at 37ºC. for 30 min. Keep this solution after incubation (for use in step 4).
- Wash 3x 3 min. in dH20.
- Add concentrated ammonium hydroxide dropwise with stirring to the silver nitrate solution reserved from step 2. Add only enough to dissolve the dark initial precipitate but not more.
- Incubate sections in this solution for 15 min. at 37ºC. Again, save this solution for use in step 6.
- Wash sections in 0.1% ammonium hydroxide 3x 2 min. at room temperature.
- Add 350 μl developer solution (0.2 ml 37% formaldehyde, 12 ml dH20, 12.5 μl 20% nitric acid and 0.05 g citric acid) to the silver hydroxide solution saved from step 4.
- Stain sections in this solution for 10 min.until they turn black.
- Wash in 0.1% ammonium hydroxide 3x 2 min. and dH20 3x 2 min.
- Tone in 0.2% gold chloride for 5 min.
- Fix in 5% sodium thiosulfate for 1 min.
- Wash in dH20, dehydrate in alcohols then xylene and mount.
Example of axonal silver staining: 8 μm thick paraffin embedded paraformaldehyde fixed sections of EAE mouse brains |