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 Alzeimer's disease
|20% silver nitrate solution||15 minutes in 30° C oven|
- Preheat the solution to 60° C in an oven or waterbath.
- Add slides to the warm solution for 15 minutes in 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.
- Check silver development on nerve fibers under the microscope.
- Background should be golden brown.
- Nerve fibers should be turning black.
|Fresh tap water||3 changes|
|5% sodium thiosulfate (hypo)||2 minutes|
|Fresh tap water||Wash well|
Post staining procedure: Tissue section should be dehydrated with 95% and absolute alcohols. Follow with 2 changes of xylene and then coverslip.
- Axons and neurofibrillary tangles - Black
- Plaque and amyloid - Brown to dark brown
- Background - Golden brown
Bielschowsky stain of brain section showing neurofibrils