Sample type required: Deparaffinized and rehydrated tissue section (6–8 μ) on positively (+) charged slides
Preferred fixative: 10% neutral buffered formalin (NBF)
Control: Cerebral cortex of a known case of Alzheimer's disease
| Reagent | Time | Technical Notes |
| 20% silver nitrate solution | 15 minutes in 30° C oven | - Preheat the solution to 60° C in an oven or water bath.
- Add slides to the warm solution for 15 minutes in a 37° C oven.
|
| Distilled water | 3 changes | Rinse one slide at a time and place in a clean, dry staining jar or rack. |
| Working ammoniacal silver | 5 to 30 minutes in 37°C oven | - Make fresh right before use.
|
| Working Formalin-based developer solution | 1–5 minutes | - Check silver development on nerve fibers under the microscope.
- Background should be golden brown.
- Nerve fibers should be turning black.
|
| Fresh ammonia water | wash | |
| Distilled water wash | 3 changes | |
| 5% sodium thiosulfate | 2 minutes | |
| Fresh tap water | Wash well | |
Post-staining procedure: The tissue section should be dehydrated with graded alcohols, beginning with 95%. This should be followed by 2 changes of xylene and then a coverslip.
Expected results:
- Axons and neurofibrillary tangles - Black
- Plaque and amyloid - Brown to dark brown
- Background - Golden brown
Limitations:
- Slides should not be handled with metal forceps or any metallic substance as a black precipitant will form from exposure to silver solution.
