Knowledge Base › Troubleshooting Atlas › Special stains
Reticulin stain over-impregnated (too black)
What it looks like
The slide appears excessively dark with pronounced black staining of reticulin fibers, obscuring cellular details.
Where it usually appears: Typically observed in liver or kidney biopsies where reticulin fibers are present.
Likely causes
- Prolonged exposure to the impregnation solution
- Inappropriate reagent concentration
- Inadequate washing after staining
Immediate checks
- Verify staining time against protocol
- Check reagent concentration against specifications
Corrective action
- Reduce impregnation time in future preparations
- Dilute the impregnation solution if necessary
- Increase washing time after staining
Preventive action
- Standardize staining protocols across the laboratory
- Regularly calibrate and maintain equipment used for staining
This atlas is for educational purposes for laboratory professionals. It does not replace your institutional SOPs, manufacturer instructions, validated protocols or pathologist judgment. Adapt any action to your laboratory and equipment.
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