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With the outbreak of the coronavirus pandemic, numerous new terms have come about to describe testing practices. One of the most common testing forms for COVID-19 is rapid lateral flow testing. By now, most people have more than likely used a lateral flow test. These tests are a commonly required travel stipulation, with Covid 19 travel testing becoming he norm in many countries around the world.

What Is A Lateral Flow Test?

Lateral flow tests are used to indicate the presence of a target substance. In COVID testing, they can demonstrate whether the virus is present. However, lateral flow tests are common and versatile diagnostic devices that have been used long before the coronavirus pandemic.

Lateral flow testing is used across industry sectors, including pharmaceutical, environmental, animal, food, and crop health testing. When used in humans and animals, they can confirm the presence or absence of a specific pathogen or biomarker.

The most widely known kind of lateral flow test strip is the pregnancy test.

Numerous names are widely used to refer to lateral flow testing, varying across sectors and countries. The most common terms are Lateral flow test, Lateral flow device, Lateral flow assay, Lateral flow immunoassay, Express test, Quick test, Rapid test and Test strip.

How Does Rapid COVID Testing Work?

Rapid tests help to check if someone has COVID-19, whether they are experiencing symptoms or not. Research shows that lateral flow tests are reliable to indicate the presence of coronavirus. They provide quick results and do not need to be sent to a lab to be read and interpreted. You should remember that health insurance companies will not routinely cover the costs of Covid tests, so you will need to find private providers.

The test kit is a small 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 the SARS Cov2 antigen that causes coronavirus as we know it.

The test paper shows two lines. The first, indicated ‘C’, is a control line that confirms that the test is working correctly. The second line, indicated’ T’, will show whether coronavirus is present.

Lateral flow testing involves taking a sample from the back of the throat near the tonsils and the nose, or from the nose only, using a swab.

The swab is dipped into an extraction solution which is dripped onto the device’s paper pad. When a sample is added, the pad absorbs it and begins to change the colour of the test paper. In the viewing window, either a negative, positive or void result is visible. One line appears next to ‘C’ if the test is negative.

If two lines appear, next to ‘C’ and’ T’, the test is positive, even if the lines are faint. Your lateral flow test is void if no lines appear or if one line appears next to’ T’.

How Do You Use a Lateral Flow COVID Test?

You can get a lateral flow COVID test at a test centre or test yourself at home. A trained person will perform the test for you in many testing centres. If you are at a self-test site and need support, you can ask one of the trained helpers present to guide you.

If you are performing a rapid COVID test on yourself, you should first:

  • Read through the instructions in the test kit
  • Wash your hands with soap or use a hand sanitiser
  • Lay each item of the test kit on a clean surface
  • If your test does not come with a pre-filled tube, fill the tube with the liquid provided and close the lid
  • Place the tube in the holder
  • Blow your nose
  • Wash your hands again

Once you are prepared, perform either a nasal swab or a throat and nose swab, depending on your kit’s instruction. For a throat swab, open your mouth wide and rub the swab over your tonsils (or where they would have been). Avoid the end of the swab touching your teeth, tongue and gums. With the same swab, wipe the inside your nose as described in the instructions. If your test requires a nose swab only, use the swab to wipe the inside your nose as the test kit instructions tell you.

To complete the lateral flow test:

  • Put the swab end of the stick into the tube and mix with the liquid
  • Squeeze two drops of the sample from the tube onto the test strip
  • Check the waiting time for your test kit in the instructions
  • Wait for the required time before checking the result
  • Don’t wait longer than the specified waiting time as this can affect the results

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