What should you know about double immunohistochemistry?

The result is interpreted alongside the tissue appearance, clinical information, and any other pathology tests. It is a way of adding detail to a tissue examination, not a diagnosis by itself.

Immunohistochemistry uses antibodies designed to bind to selected substances, called markers, in prepared tissue. A visible stain shows where a marker is present. In a double stain, two marker targets are assessed on the same section, often with different colours or other distinguishable signals.

Looking at both signals together can help distinguish cell types, identify cells that share a marker pattern, or clarify how an abnormal area relates to surrounding tissue. The method may be useful when a single stain does not provide enough context. A pathologist still considers whether the staining is present, where it appears, and how strongly or consistently it is seen.

The test is performed on tissue obtained during a biopsy or another procedure. It does not usually require a separate sample from you, although the laboratory may need suitable preserved tissue.

You generally do not need to prepare for the laboratory stain itself. Keep the appointment or procedure plan provided by your care team, and tell them about medicines, allergies, or health conditions that could affect the biopsy or tissue procedure.

When the report is available, ask which markers were tested, what the combined pattern showed, and whether the finding changes the diagnosis or next step. Some results support classification of a tumour, while others help separate similar-looking conditions. The report may also say that the stain was inconclusive or that additional testing is needed.

For background on the broader laboratory method, see [Immunohistochemistry](/technology/immunohistochemistry/). If tissue was collected for testing, [Biopsy](/treatments/diagnostics-and-staging/biopsy/) explains how that procedure fits into diagnosis.

Double immunohistochemistry itself is a laboratory analysis, so it does not create symptoms that need urgent review. Seek prompt medical help after a biopsy or related procedure if you develop heavy bleeding, worsening pain, spreading redness, fever, or drainage from the site.

Contact the team handling your report if the expected result has not arrived or if you do not understand whether the finding is conclusive. New or worsening symptoms should be assessed on their own; a tissue stain cannot determine the cause of every symptom.

Which two markers were examined, and what do they indicate in this tissue?

Were the markers seen in the same cells, separate cell groups, or the surrounding tissue?

Does this result confirm a diagnosis, narrow the possibilities, or point to another test?

How will the pathology finding affect treatment planning or the next appointment?