The<unk>  is an immunological medical test that can be used to detect the presence of either specific antibody or specific antigen in a patient's serum, based on whether<unk>  fixation occurs. It was widely used to diagnose infections, particularly with microbes that are not easily detected by culture methods, and in rheumatic diseases. However, in clinical diagnostics labs it has been largely superseded by other serological methods such as ELISA and by DNA-based methods of pathogen detection, particularly PCR.
Complement fixation test
Lupus band test
Heterophile antibody test
Latex fixation test
Total complement activity
Direct fluorescent antibody
Tetramer assay
Direct agglutination test