ABC Immunohistochemistry Explained

ABC commonly refers to an avidin-biotin complex used in the staining process. An antibody binds to a selected target in a thin tissue section. Linked detection components then build a visible signal at the target site, allowing the pathologist to assess where staining appears within the cells and how strong or widespread it looks. A panel of markers is often more informative than one stain because different cell types can share individual proteins.

Read the immunohistochemistry findings together with the main pathology diagnosis rather than treating a positive or negative marker as a diagnosis by itself. The report may describe staining as nuclear, cell-surface, or cytoplasmic, which helps with interpretation. Ask which markers were tested, what question the panel addressed, and whether the tissue sample was adequate. Further stains, molecular tests, or review by a specialist pathologist may be suggested when findings remain uncertain.

The staining procedure happens in a laboratory and does not itself create symptoms or require emergency care. Follow the biopsy team's instructions for the sample site. Seek prompt clinical advice for increasing redness, warmth, swelling, discharge, fever, persistent bleeding, or pain that is worsening after the biopsy. Contact the treating team if you have received the report but have no appointment to discuss what the combined findings mean for the next decision.

Ask what diagnosis the overall tissue pattern supports, which marker findings were decisive, and whether any result was inconclusive. It can also help to ask whether the findings identify the tissue of origin, influence treatment selection, or require another sample.