complement-fixation test

complement-fixation test

n.

An immunological test for determining the presence of a particular antibody in which serum is treated in a manner that allows existing antibodies to accept and bind to a known amount of antigen. If binding occurs the presence of the antibody is verified and its concentration in the serum can be calculated based on the amount of antigen added to the system.

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complement-fixation test,

any serologic test in which complement fixation is detected, indicating the presence of a particular antigen. Specific C-F tests are used to aid in the diagnosis of amebiasis, Rocky Mountain spotted fever, trypanosomiasis, and typhus. They are rarely used in clinical practice today.

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complement (kom´plment),

n one of 11 complex, enzymatic serum proteins. In an antigen-antibody reaction, complement causes lysis. Complement is also involved in anaphylaxis and phagocytosis.

complement fixation,

n an immunologic reaction in which an antigen combines with an antibody and its complement, causing the complement factor to become inactive, or “fixed.”

complement-fixation test (C-F test),

n a serologic test in which complement fixation is detected, indicating the presence of a particular antigen. The Wassermann test for syphilis is a C-F test, used to detect amebiasis, Rocky Mountain spotted fever, try-panosomiasis, and typhus.