Definition

A laboratory test that checks for the presence of antibodies or other substances in a blood sample. Antibodies are proteins made by the body’s immune system in response to a foreign substance or microorganism, such as a virus. Serology tests look for certain antibodies to see whether a person has been exposed to or infected with a virus or other infectious agent. Sometimes antibodies are made against the body’s own tissues. In that case, serology tests are used to look for those antibodies and help diagnose certain immune system disorders, such as autoimmune disorders and immunodeficiency disorders. Serology tests are also used to determine a person’s blood or tissue type.