Lateral flow tests are designed to enable rapid testing without the need for laboratory equipment.
Lateral flow antigen testing
Lateral flow testing is a fast and simple way to test people who do not have symptoms of COVID-19, but who may still be spreading the virus. In some circumstances lateral flow tests can also be used for other diagnostic tasks.
The tests are easy to use and give results in 30 minutes. Those who test positive must immediately self-isolate to avoid passing the virus on to others.
How lateral flow testing works
Lateral flow is an established technology, adapted to detect proteins (antigens) that are present when a person has COVID-19. The best-known example of a lateral flow test is the home pregnancy test kit.
The test kit is a hand-held device with an absorbent pad at one end and a reading window at the other. Inside the device is a strip of test paper that changes colour in the presence of COVID-19 proteins (antigens).
Negative result: one line next to C shows the test is negative.
Positive result: two lines, one next to C and one next to T, even faint lines, shows the test is positive. You or your test provider must report this test result to the NHS.
Void: no lines, or one line next to T, means the test is void. You will need to re-take with a fresh test kit.
If you get a positive result you must self-isolate immediately, preventing further transmission of the virus.
A negative result means that active coronavirus infection was not detected, at the time of the test. However, this does not guarantee that you do not have coronavirus. You should continue to follow coronavirus rules, including regular hand washing, social distancing and face coverings where required.