What should you know about immunohistochemistry primary antibody?

The laboratory chooses a primary antibody for the protein being investigated. In a prepared tissue section, the antibody recognises and attaches to that target. In a direct method, the primary antibody carries the detectable label; in an indirect method, a labelled secondary antibody binds to it. The resulting signal may show whether the protein is present and where it is found in the cells. Antibody binding is interpreted with tissue structure, controls, and the clinical question, because a marker result has meaning only in context.

Check the report for the target marker, the specimen, and the description of staining. Ask whether the antibody was used as part of a panel and whether the controls were acceptable. A positive or negative label may not answer the whole diagnostic question, and an unexpected pattern may lead to additional stains or molecular testing. Keep the complete report available for every clinician involved in your care.

Ask the clinic for clarification if the report names a primary antibody but does not explain the integrated diagnosis, or if testing is pending because tissue is limited. After tissue collection, seek urgent help for uncontrolled bleeding, fainting, severe pain, or difficulty breathing. These symptoms require clinical assessment independently of the antibody result.

Which protein did the primary antibody target? What does its staining location mean in my tissue? Was a secondary antibody or another detection method used? Are more tests needed to complete the interpretation?