Immunohistochemistry

Immunohistochemistry (IHC) uses antibodies to detect antigens in a tissue sample. It’s one lab technique a pathologist may use to check for signs of disease following a biopsy. IHC is commonly used to diagnose cancer, predict treatment response and determine likely outcomes (prognosis) of the disease.

What is immunohistochemistry (IHC)?

Immunohistochemistry (IHC) is a lab technique pathologists use to look for signs of disease in a tissue sample. A pathologist uses lab tests to diagnose medical conditions.

As part of your diagnosis, a healthcare provider may remove tissue and send it to a lab for testing. For example, they may remove part of a tumor and send it to a lab to test for cancer cells. This is called a biopsy. An IHC is just one method a pathologist may use to study the sample once it arrives at the lab.

IHC is the most common type of immunostaining. Immunostaining involves using antibodies and special markers to “label” parts of a tissue sample so they’re easier for pathologists to identify.

The word “immunohistochemistry” provides clues about what’s involved:

Immuno means relating to your immune system. Your immune system detects substances in your body (called antigens). It makes antibodies to find and destroy antigens that don’t belong, like pathogens (viruses, bacteria, fungi and parasites) and cancer cells. An IHC uses the antigen-finding properties of antibodies to detect and grab onto antigens in a tissue sample. Antibodies stain the sample so the pathologist can see the antigens they’re attached to when viewed beneath a microscope.

Histo means tissue. An IHC examines a tissue sample.

Chemistry studies the tiny building blocks that make up all matter, including human tissue. An IHC uses a microscope to see otherwise invisible antigens that may indicate diseases.