CEA is detected in histological samples using immunohistochemistry (IHC). Tissue samples are first fixed and embedded in paraffin. Thin sections are then cut and placed on slides. These sections are treated with specific antibodies against CEA. If CEA is present in the tissue, the antibodies will bind to it, and a visible reaction will occur, often detected with a secondary antibody that is enzyme-linked or fluorescently labeled. This allows pathologists to visualize the presence and distribution of CEA in the tissue sample under a microscope.
