WordNet records no synonym and no antonym for complement fixation test. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a blood test in which a sample of serum is exposed to a particular antigen and complement in order to determine whether or not antibodies to that particular antigen are present; used as a diagnostic test
Synonyms, antonyms and the broader and narrower relations for complement fixation test come from Princeton University’s WordNet. Full sources and licences.