This procedure is also called saponification. It reverses the effects of acetylation and restores PAS positivity. However, this is not absolute, and proceeds at different rates for different compounds. It may therefore be used to identify compounds based on double criteria: A) blocking of staining by acetylation, and B) restoration of staining by deacetylation.
Solution
| Material | Amount | |
|---|---|---|
| Ethanol, absolute | 30 | mL |
| Distilled water | 10 | mL |
| Ammonia water, 28% | 10 | mL |
Procedure
- Celloidinise previously acetylated sections.
- Place into the solution in a sealed container at 37°C for 4-24 hours.
- Rinse well with 80% ethanol.
- Continue on with the staining method.
| Tissue | Temperature | Time | State |
|---|---|---|---|
| Glycogen | 37°C | 4-6 hours | Restored |
| Intestinal mucins | 37°C | 4-6 hours | Restored |
| Basement membrane | 37°C | 16 hours | Restored |
| Brush borders | 37°C | 16 hours | Restored |
| Retinal rods | 37°C | 24 hours | Restored |
References
- Lillie, R.D., (1954)
Histopathologic technique and practical histochemistry Ed.2
Blakiston, New York, USA
