Antigen tests and antibody tests are often immunoassays (IAs) of one kind or another, such as dipstick IAs or fluorescence immunoassays, however RAT is an immunochromatographic assay which 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, if the sensitivity and specificity are relatively low for the test then the results should be evaluated on the basis of confirmatory tests like PCR testing or western blot.