Knowledge Base › Troubleshooting Atlas › IHC
Patchy / regional IHC staining
Also known as: uneven staining, localized staining
What it looks like
Staining is inconsistent, with some areas showing strong positivity while others are weak or negative.
Where it usually appears: Commonly observed in tissue sections with heterogeneous antigen expression or during suboptimal processing.
Likely causes
- Inadequate antigen retrieval
- Improper dilution of primary antibody
- Inconsistent incubation times
- Poor tissue fixation
- Insufficient washing steps
Immediate checks
- Verify antibody dilution and expiration
- Check fixation time and method
- Ensure proper antigen retrieval technique
Corrective action
- Optimize antigen retrieval conditions
- Adjust antibody concentration and incubation time
- Increase washing duration to reduce background noise
Preventive action
- Standardize fixation and processing protocols
- Regularly calibrate and maintain equipment
- Train personnel on IHC techniques and troubleshooting
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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