Covid tests; what you need to know.
Most accurate test is the PCR (or RNA or molecular) test. This test looks for a bit of the internal part of the virus. This is the standard test performed by NHS testing services.
Less accurate is the antigen (or rapid or Liverpool) test. This test looks for pieces of the coating of the virus. It misses between 2 -20% of infections; a result is negative although the person actually has the virus. It is not suitable for screening employees without symptoms.
The antibody test indicates only that a person has had the infection at some stage in the past. It does not necessarily indicate immunity to infection, this is unknown at present.
For accurate results the swabs should be taken, and the results read, by a health care professional.