Knowledge Base › Troubleshooting Atlas › IHC
DAB too strong / over-developed
Also known as: overdeveloped DAB, excessive DAB staining
The slide shows dark brown to black staining that obscures cellular details. The background may also appear overly dark.
Where it usually appears: Typically appears in immunohistochemistry (IHC) slides after excessive incubation with DAB or prolonged development time.
- Prolonged incubation time with DAB
- High DAB concentration used
- Inadequate rinsing between steps
- Inappropriate temperature during development
- Check timing of DAB incubation
- Verify DAB concentration used
- Inspect rinsing protocol adherence
- Dilute DAB solution for future use
- Reduce incubation time for next batch
- Enhance rinsing steps to remove excess DAB
- Establish strict timing protocols for DAB incubation
- Regularly calibrate timers used in the lab
- Conduct pilot tests to optimize DAB concentration
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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