Lateral Flow Tests (“LFTs”) have been available for use in industry and within the home for over 30 years. They are a simple, accurate and cost-effective solution to sometimes complicated questions, and can provide answers on important issues, that can range from “is this material contaminated?” to “am I pregnant?!”
Today the range of LFTs available is vast. From point-of-care tests used by doctors and nurses to quickly assess patient conditions, to self-tests available to buy and use at home for topics such as fertility, menopause, infectious diseases, vitamin deficiencies, HIV, hypothyroidism, ulcers and lots more, with new tests being developed all the time.
So, How Does This Technology Work?
LFTs are based on the principle of detecting a specific marker in an identified sample type. This means that each test will identify its specific target(s) within the appropriate sample, which can be anything from fuel to blood. Test and control lines on the LFT contain indicators (known as reagents) which bind with the sample to display a result. If you’re really into the science behind LFT technology, you can watch our video on how LFTs work here.
Control Lines & Test Lines – It’s All Greek To Me…
A LFT will have a control line that, provided the test has been performed correctly, will always be present. In the absence of a control line the test result is invalid and should be discarded. In contrast, the LFT will have one or multiple test lines that may show up in the test wait time.
In the case of a pregnancy test, for example, ordinarily one line will appear for a negative result (control line only) and two lines for a positive result, (control line and test line). The lines are usually marked on the device as T (test), and C (control) to aid result interpretation…
Following Instructions to the Letter
It’s critical to carefully follow the instructions provided with any LFT, to ensure a usable sample is collected correctly, not contaminated, and applied to the device in the correct way to get an accurate result. Make sure to sanitise the work surface and wash your hands, only remove the test device from the foil when you are ready to use the LFT and keep the test the right way up at all times. The presence or absence of a test line will have a different meaning depending on what is being detected. It is, therefore, extremely important to interpret the result in accordance with the instructions. Some LFTs can deliver multiple results, for example Abingdon’s Simply Test range includes a combination COVID-19 / Flu A+B test that detects both viruses on one test, so it’s critical to collect the sample precisely for true reads.
Why Are We Waiting?
Once the sample is applied to the device, we recommend setting a timer to ensure you read the result within the specified window. Control lines may appear instantly but is critical that you still wait for the specified time before interpreting. If the test device is read before the time specified in the instructions or is left to develop longer than the specified time, you may receive a false result and will need to repeat the test.
Is That a Line?
Once it’s time to interpret the results, remember not all test lines and control lines will be of the same intensity. Read the instructions to be sure; but for many tests, a test line of any intensity is an indication that that the specific target has been detected. Always interpret your results in a well-lit area.
Test. Know. Act.
Our mission is to improve life by making rapid testing accessible to all, and we’re constantly on the lookout for new products to add to our range. Our CDMO parent company, Abingdon Health, is also working with innovative clients around the world to develop new tests to bring to market. Just one example of a test we’ve been working on is the world’s 1st ever saliva pregnancy test, SaliStickTM. Follow us on social media to stay tuned in for the latest news and tests coming to the Abingdon Simply Test range.