It’s a given that most kids will try to skip school just about any time they think they can. They’ll claim their belly hurts, they’ll fake a fever – anything to get out of class and another homework assignment.
And thanks to the COVID pandemic, kids now have a new illness to claim they have. Some, in fact, have found a way to fake a positive COVID test.
As you well know, at-home COVID tests, usually in the form of lateral flow tests or LFTs, have been sold over the counter for some time now. And in Liverpool, England, a few unruly youths have figured out how to use soda, or ‘pop’ as it is referred to in my native Midwest, to fake a positive result.
According to BBC, the deception was first seen on the popular TikTok social media platform back in December. And since then, a number of children have successfully used it to get out of their classes, with a two-week quarantine at home, of course.
As both TikTok and BBC explain, the process is quite simple. All you need is some soda or orange juice and an LFT device.
If you’ve ever used an LFT device, you’ll know that it works similarly to a pregnancy test. A sample of supposedly infected DNA is placed on a strip of test paper, called nitrocellulose, which then is soaked into the device and gives a result in a matter of minutes.
In the case of an LFT, the DNA sample is usually swabbed from the back of the nose or throat and then mixed with “liquid buffer,” designed to ensure that the pH of the sample stays at an optimum level before being introduced to the testing strip.
Once dropped onto the testing device, should COVID proteins or antibodies be found in the sample, a red line appears, followed by a second red line indicating the test is working and concluded successfully.
As BBC explains, the red line is actually gold nanoparticles and other antibodies which adhere themselves to any COVID virus present in the sample.
“The fluid wicks up the nitrocellulose strip and picks up the gold and antibodies. The latter also bind to the virus, if present. Further up the strip, next to the T is more antibodies that bind the virus. But these antibodies are not free to move – they are stuck to the nitrocellulose. As the red smear of gold-labeled antibodies passes this second set of antibodies, these also grab hold of the virus. The virus is then bound to both sets of antibodies – leaving everything, including the gold, immobilized on a line next to the T on the device, indicating a positive test.”
But apparently, this red line, and a false positive, also appears when soda or orange juice, added to the liquid buffer, is introduced to the test strip.
So what makes the science behind this work?
Well, as of right now, that’s not particularly clear. The current theory and the one explained by BBC is that the drinks are acidic enough to confuse the antibodies included in the test. The citric acid in both orange juice and sodas have a relatively low pH level, which would clash with the near-neutral pH of the antibodies.
Even the addition of the liquid buffer can’t remedy the clashing levels. And so it is believed that because the pH levels are imbalanced, the antibodies get confused and don’t know how to react, resulting in less than trustworthy results.
The fad of faking the test has become so prolific, in fact, that one Liverpool school has had to issue a schoolwide notification to parents about it, warning of potential false positives in their children’s test results.
Thankfully, as BBC’s Mark Lorch reports, there is a way to determine if the result is actually positive or not. All you need to do is wash the test off.
“I tried washing a test that had been dipped with cola with buffer solution, and sure enough, the immobilized antibodies at the T-line regained normal function and release the gold particles, revealing the true negative result on the test.”
So, if you are in the habit of giving your children at-home COVID tests, know that there is a way to fake them. But just as easy is a way to find out whether those results are accurate or not…