What should you know about immunoassay and immunohistochemistry?

An immunoassay usually measures a substance in a fluid such as blood. It may help detect a protein, hormone, or other marker. Immunohistochemistry examines a thin section of tissue and shows where a marker is present within cells. A pathologist studies the stained pattern alongside the tissue’s appearance.

These methods can help identify the type of cells in a sample, distinguish between conditions with similar appearances, or assess features that influence treatment choices. A marker result is one part of the assessment; it should be read with the biopsy report, imaging, symptoms, and other laboratory findings.

Ask which sample is needed and whether any preparation is required. Tell the team about medicines, allergies, recent treatment, and previous biopsy results. A tissue test begins with a sample collected during a Biopsy, while an immunoassay may use blood or another fluid.

When results are available, ask what the marker means in your specific diagnosis, whether the result is positive, negative, or inconclusive, and whether another test is needed. Do not interpret a single marker as a diagnosis without the full pathology report.

The laboratory methods themselves do not usually cause symptoms, but sample collection can leave soreness or bruising. Contact the clinical team if a biopsy site becomes increasingly painful, red, swollen, or leaky, or if you develop fever after the procedure.

Seek urgent help for heavy bleeding, fainting, severe breathing difficulty, or swelling of the face or throat. Use the contact instructions provided by your clinic if you are unsure whether a sample-related change needs review.

Ask what marker is being tested, why it matters for your case, whether the sample is adequate, and when the report will be explained. Ask whether the result could change treatment choices and how it fits with scans, symptoms, and the rest of the pathology findings.