Immunological tests:
The tests used to detect antigen or antibody in serum or in other specimens is called immunological test.
Serological tests:
The tests used to detect antigen or antibody in serum is called immunological test.
Antigen-antibody reactions with examples of each type:
| Name of Ag-Ab reaction | Example | |
1. Agglutination test | Slide agglutination | Serotyping of bacteriaBlood grouping |
| Tube agglutination | Widal test for enteric feverWeil-Felix test for rickettsial infection | |
| Latex agglutination | HbsAg detection ASO titre (antistreptolysin-O titre) estimation | |
| Particle agglutination | Detection of anti HIV antigen | |
| Haemagglutination | TPHA for diagnosis of syphilis | |
2.precipitation test | Tube precipitation test | Estimation of antibody |
| Gel diffusion | Single radial diffusion: for estimation of antibody.Double gel diffusion: For identification of antigen. | |
| CIE (counter immuno- electrophoresis) | Detection of cryptococcus antigen in CSF. Detection of carcino-embryonic antigen (CEA). | |
| 3. Complement fixation test (CFT) | CFT for kala-azar, CFT for filarial parasite, CFT for gonococcus | |
4. Others (immunoassay using labeled reagents) | Immuno-fluorescence (IF)- Detection of T & B cells,Detection of treponemal antibody in syphilitic patients | |
| Enzyme-linked immunosorbent assay – . HIV antibody,Hepatitis-B panel (HbsAg, HbeAg, Anti-HBs,Anti-HBc) | ||
| Radio-immuno assay (RIA) – Detection of HbsAg. | ||