All microbial species have one antigen which is unique. These antigens can be purified and used to generate specific monoclonal antibodies.
Both the things, antigen and antibodies provide a highly specific diagnostic tool.
The term ELISA stands for enzyme linked immunosorbent assay is a serological test to look for presence of particular antigen or antibody.
There are two types of assays in ELISA
Direct ELISA uses monoclonal antibodies to detect the antigen.
Indirect ELISA measures presence of specific antibody i.e. HIV antibody in a given sample.
- To evaluate either the presence of antigen or the presence of antibody in a sample
- Detection of mycobacterial antibodies in tuberculosis.
- Detection of rotavirus in feces.
- Detection of hepatitis B markers in the serum.
- Detection of enterotoxin of E. coli in feces.