Lateral flow and PCR tests are the two COVID tests that are the most widely used in the UK at the moment. These two tests have helped to limit the spread of the coronavirus and kept us safe, in partnership with the UK’s vaccination efforts.
As travel restrictions in the UK seem to be being constantly updated, so certain COVID-19 tests are becoming more useful than others. For example, under the new rules that came into effect on the 4th of October, fully vaccinated travellers entering the UK from non-red list countries no longer need to take a PCR test before departure. They still have to take a Day 2 PCR Test on arrival at the moment, but this will change at the end of October when it will be possible to take a lateral flow test instead.
Travellers arriving from a red-list country, or those that are unvaccinated, will still have to take multiple PCR tests and self-isolate for ten days at a government-approved hotel.
Both the PCR and Lateral Flow test can be got from the NHS (if you are not using them to travel abroad) or purchased through private providers, such as Fit2FlyTest.
If you are wondering what the difference between these two COVID tests is, read on:
What is a PCR test?
PCR stands for a polymerase chain reaction.
PCR COVID tests are used to screen for the presence of the viral RNA of coronavirus, which is detectable in the body before symptoms are present or before antibodies are formed. This means that the PCR test can tell whether or not somebody has the virus very early in their illness.
As part of the COVID_19 PCR tests, a substance known as polymerase is added to your nasal sample in our lab. This substance then goes to work making numerous copies of any viral RNA present in your sample, so that there is enough RNA present to signal a positive result.
Among the science profession, it is felt that the use of PCR tests can give us a clearer picture of the spread of a disease such as COVID-19. However, even PCR tests have caveats as they have to be sent away to a lab as we have here at Fit2FlyTest – meaning it can take a day or so for people to discover their results.
What is a Lateral Flow Test?
Lateral Flow Tests (LFT) are similar to PCR tests in that they are both antigen tests designed to pick up on active coronavirus infection, rather than looking for antibodies to the virus.
In a lateral flow test, a sample from your nose is placed on a small absorbent pad, with the sample then being drawn along the pad to a strip that is coated in antibodies that bind to SARS-Cov-2-Proteins. So, if these proteins are present in your sample, this will show as a coloured line on your lateral flow tests, indicating that you are infected with the virus.
The main benefit of LFT over PCR tests is that LFT does not need to be sent away to a lab for confirmation of the result – you can get your own result within half an hour. However, this increase in speed is also reflected in a lower case of accuracy.
What are the main differences between Lateral Flow testing and PCR testing?
The main differences between lateral flow and PCT tests are:
- LFT look for proteins (antigens) in the swab sample in order to detect the presence of the coronavirus. PCR tests, on the other hand, look for genetic material (known as RNA) which is the material that instructs the virus to produce the relevant proteins.
- LFT are relatively inexpensive, while PCR tests can be up to £92
- LFT results tend to be accurate generally, but positive results will need to be condirmed with a PCR test. A PCR test is accepted as being more accurate and reliable, and therefore a second test would not be needed
- LFT tests are intended for use by people who do not have symptoms of COVID-19, while PCR tests are intended for those already showing symptoms
- LFT results can be ready in 30 minutes or less, while PCR tests have to be sent to a lab for processing and so will take longer
In the end, deciding which test is best for you to take will depend on many different factors. In some cases, such as international travel, you might be ordered to take a specific test, either PCR or LFT, and so have no choice. In some cases, it might be up to you, for example, if you want to demonstrate to your colleagues at work that you are COVID free you will probably use an LFT. However, if you have COVID-19 symptoms, then you will need to take a PCR test.