How exactly do Covid-19 tests work?


Since the outbreak of Covid-19, testing for the virus has been an important method of curbing the spread and allowing us to understand transmission rates. A number of different methods have been developed to test for Covid-19 and, in the UK, we use two different kinds. The first kind are the tests that are sent off to a lab and are performed mostly in designated testing sites, though home kits are now available. These tests are called PCR tests and a result is sent to you from a lab. The other form of test readily used in the UK is the at-home testing kits, like the Hughes lateral flow covid test, which can be done without leaving the house.

But how do these tests work?

How do the different Covid-19 tests work?

PCR Tests

PCR tests detect the virus’s RNA (genetic material) in a swab taken from the nose and throat. Enzymes, called DNA Polymerase and Reverse Transcriptase, are added to this sample to replicate the genetic material in the swab, making sure there is enough of the sample to properly test. The test then involves primers and probes which attach themselves to specific sequences within Covid-19’s genetic code to signal the presence of the virus. The primers work by targeting unique sequences within the code.

Rapid antigen testing

The at-home testing kits, also known as rapid antigen testing – like the Healgen rapid Antigen test – work in a different way to the PCR tests. In these tests, a sample is taken from a nose swab and is placed on an absorbent pad. The sample is then drawn along a strip of antibodies which bind to the proteins in Covid-19. The test works similarly to pregnancy tests in that, if these proteins are present, a coloured line will show indicating their presence.

How accurate are the tests?

Both tests are used in confirming a diagnosis of Covid-19, but how accurate are these tests?


PCR tests are a highly effective testing process for confirming the presence of Covid-19. This is because the PCR tests don’t pick up ‘cross-activity’ (detection of other common viruses) as they are created specifically for the Covid-19 genome. The PCR test is also accepted as full confirmation of a positive test result by most employers and is recommended after a positive rapid antigen test.

How accurate is the rapid Covid test?

The rapid antigen tests – also known as lateral flow tests – are not as effective as PCR tests but they are still incredibly effective in helping to diagnose Covid sufferers and prevent transmission rates. They are used twice weekly by people in a number of professions and are recommended even if you don’t have symptoms. 

Rapid antigen testing at home is easy in the UK and you can order up to two packs of the tests at a time. The tests are a quick and effective way to confirm that you are Covid-19 free, or to let you know you need to do a PCR test. These tests are offered to those without symptoms of Covid-19 to stop the spread of the virus through people who are asymptomatic.

How quickly will I get my results?

PCR testing

As PCR testing involves sending your sample to a lab, these results can take between 24 and 48 hours to come through. When you are tested, you are given a unique code so that if your results aren’t with you within 48 hours you can call and quote this code to ensure you get your results back.

Rapid antigen testing

Results for at-home testing will only take thirty minutes to produce and so you will be able to confirm a negative, or positive test results very quickly.

Can I pay for covid 19 antibody test?

Yes, you can. You can purchase a Healgen test from and have it delivered straight to your home.

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