What should you know about double staining immunohistochemistry?

A thin section from a biopsy is treated with antibodies that bind to selected proteins. Each antibody produces a different colour or visual signal. Under a microscope, the pathologist assesses where each signal appears, whether the signals overlap, and which cells carry each marker. This can add detail when one marker alone cannot distinguish tumour cells from surrounding immune, supporting, or normal tissue. The result may be described as positive, negative, weak, strong, focal, or diffuse, but those words only have meaning in relation to the markers and tissue pattern being assessed.

No special preparation is needed for the staining itself because it is performed on tissue already collected. Ask which markers were selected and what clinical question they address. Your doctor may combine the report with the biopsy diagnosis, imaging, examination, and other laboratory tests before discussing treatment. Keep the wording of the pathology report and ask whether the sample was adequate, whether additional staining is planned, and when the findings will be reviewed. Do not treat a single marker as a diagnosis without the full pathology interpretation.

Double staining does not create a new physical symptom because it is a laboratory process. Seek prompt advice for increasing pain, redness, swelling, drainage, fever, or bleeding at the biopsy site. Emergency care is needed for heavy bleeding, fainting, severe breathing difficulty, or sudden confusion. Arrange follow-up to discuss the pathology report, particularly if the report uses terms you do not understand or recommends another sample.

Which two proteins were stained, and why? Do the signals occur in tumour cells, surrounding cells, or both? What do the intensity and distribution mean in my report? Could the result change staging or treatment choices? Is more tissue testing required?