Troubleshoot Immunohistochemistry Performance – Support Atlas Antibodies

Introduction

This guide helps you troubleshoot antibody performance in immunohistochemistry when the antibody is not giving the expected result. In this case, the antibody is validated for WB and ICC-IF in cell lines, but not approved for IHC in tissue sections. If you need an antibody for IHC, consider the sister product HPAXXXXXX, which is approved for IHC.

Issue description

The antibody is not working as expected in IHC on tissue samples. The most likely reason is that the product has not been approved or validated for this application. Atlas Antibodies standard IHC workflow uses formalin fixed paraffin embedded tissues, antigen retrieval in citrate buffer pH 6 in a pressure boiler, a polymer-based HRP secondary, and a DAB reaction.

Signs

No specific staining signal in tissue sections
Weak or inconsistent staining compared with expected expression patterns
High background staining or non-specific signal
Good performance in WB or ICC-IF, but poor performance in IHC

Basic troubleshooting steps

Use the checklist below to rule out the most common causes before changing your protocol.

Confirm that the antibody is validated for IHC on tissue sections.
Check whether the sample type matches the validation data, especially FFPE tissue.
Verify that antigen retrieval conditions are appropriate for the target and antibody.
Review the primary antibody dilution, incubation time, and detection system.
Confirm that positive and negative controls were included in the run.
Make sure the tissue fixation and processing conditions are suitable for IHC.

Diagnostic tools and resources

Product datasheet and validation images
Application-specific validation data
IHC protocol for FFPE tissue sections
Control tissue known to express the target antigen
Matched negative control tissue or isotype control

Advanced troubleshooting steps

Step 1: Verify application suitability

Check the product documentation to confirm whether the antibody is validated for IHC. If the antibody is only approved for WB and ICC-IF in cell lines, it may not perform reliably in tissue IHC even if it works in other applications.

Step 2: Compare with an IHC-validated alternative

If your experiment requires tissue IHC, consider switching to HPAXXXXXX or another antibody with documented IHC validation. Use the antibody that best matches your sample type and intended application.

Step 3: Review the IHC workflow

For FFPE tissues, confirm that your workflow includes formalin fixation, paraffin embedding, antigen retrieval in citrate buffer pH 6 using a pressure boiler, a polymer-based HRP secondary, and DAB detection. Adjust one variable at a time if you need to optimize signal or reduce background.

Step 4: Re-run with controls

Repeat the assay with a known positive control tissue and a negative control. If the control fails, the issue is more likely related to protocol conditions, sample quality, or antibody suitability than to the target sample itself.

Contact support

If you need help selecting an antibody for IHC or interpreting validation data, contact Support Atlas Antibodies with your product name, lot number, sample type, fixation method, retrieval conditions, and detection system. Include images of the staining result if available.

Additional resources

Atlas Antibodies product pages and validation data
Application notes for IHC on FFPE tissues
Company information and scientific background at https://www.atlasantibodies.com/company/

Conclusion

When an antibody performs well in WB or ICC-IF but not in IHC, the most important question is whether it was validated for tissue staining in the first place. Matching the antibody to the correct application, sample type, and protocol is the best way to achieve reliable IHC results.

Disclaimer

This guide is intended for general troubleshooting only. Experimental results can vary depending on sample quality, protocol conditions, and laboratory setup. Use your own scientific judgment and consult product documentation before making changes to your assay.