Knowledge Base › Troubleshooting Atlas › H&E staining
Eosin too weak or absent
What it looks like
Eosin staining appears pale or completely absent, resulting in a lack of contrast against the hematoxylin-stained nuclei.
Where it usually appears: Typically observed in tissue sections that require adequate eosin staining after H&E processing.
Likely causes
- Insufficient eosin concentration in the staining solution
- Inadequate staining time
- Improper pH of the eosin solution
- Contamination of eosin with water or other substances
Immediate checks
- Verify eosin concentration in the staining solution
- Check the pH of the eosin solution
- Inspect for any visible contamination in the eosin solution
Corrective action
- Adjust eosin concentration if too low
- Increase staining time if inadequate
- Prepare a fresh eosin solution if contaminated
Preventive action
- Regularly check and calibrate eosin solutions
- Maintain proper storage conditions for eosin reagents
- Train staff on correct staining protocols
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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