The standard methods of testing for presence of SARS-CoV-2 are nucleic acid test, which detects the presence of virus RNA fragments. As these tests detects RNA but not infectious virus, it's "ability to determine the duration of infectivity of patients is limited. The test is typically done on respiratory samples obtained by nasopharyngeal swab; however, a nasal swab or sputum samples may also be used. Results are generally available in hours. The WHO has published several testing protocols for the disease.
Several laboratories and companies have developed serological tests which detect antibodies produced by the body in response to infection. Several have been evaluated by Public Health England and approved for the utilization in UK.
On 7th September, UK government issued "guidance for procedures to be implemented in laboratories to provide assurance of positive SARS-CoV-2 RNA results during period of low prevalence, when there is a reduction in the predictive value of positive tests results.
