Rapid antigen test
A rapid antigen test (RAT) is a rapid diagnostic test suitable for point-of-care testing that directly detects the presence or absence of an antigen. This distinguishes it from other medical tests that detect antibodies (antibody tests) or nucleic acid (nucleic acid tests), of either laboratory or point of care types.
Common examples of RATs or RADTs include:
- Rapid strep tests (for streptococcal antigens)
- Rapid influenza diagnostic tests (RIDTs) (for influenza virus antigens)
- Malaria antigen detection tests (for Plasmodiumantigens)
Antigen tests and antibody tests are often immunoassays (IAs) of one kind or another, such as dipstick IAs or fluorescence immunoassays. While RAT is an immunochromatographic assay that gives visual results that can be seen with the naked eye. It is considered to be qualitative but a person experienced in RDT testing can easily quantify the results. Being a screening test, the results should be evaluated on the basis of confirmatory tests like PCR testing or western blot.