Beautiful Virgin Islands

Wednesday, Jun 25, 2025

How children are spoofing Covid-19 tests with soft drinks

How children are spoofing Covid-19 tests with soft drinks

Some children have found a devious method to get out of school – using cola to create false positive Covid tests. How does it work?

Children are always going to find cunning ways to bunk off school, and the latest trick is to fake a positive Covid-19 lateral flow test (LFT) using soft drinks. [Videos of the trick have been circulating on TikTok since December and a school in Liverpool, UK, recently wrote to parents to warn them about it.] So how are fruit juices, cola and devious kids fooling the tests, and is there a way to tell a fake positive result from a real one? I’ve tried to find out.

First, I thought it best to check the claims, so I cracked open bottles of cola and orange juice, then deposited a few drops directly onto LFTs. Sure enough, a few minutes later, two lines appeared on each test, supposedly indicating the presence of the virus that causes Covid-19.

It’s worth understanding how the tests work. If you open up an LFT device, you’ll find a strip of paper-like material, called nitrocellulose, and a small red pad, hidden under the plastic casing below the T-line. Absorbed on the red pad are antibodies that bind to the Covid-19 virus. They are also attached to gold nanoparticles (tiny particles of gold actually appear red), which allow us to see where the antibodies are on the device. When you do a test, you mix your sample with a liquid buffer solution, ensuring the sample stays at an optimum pH, before dripping it on the strip.

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 (for test), are 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-labelled antibodies pass 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, immobilised on a line next to the T on the device, indicating a positive test.

Gold antibodies that haven’t bound to the virus carry on up the strip where they meet a third set of antibodies, not designed to pick up Covid-19, stuck at the C (for control) line. These trap the remaining gold particles, without having to do so via the virus. This final line is used to indicate the test has worked.

The acidity of many soft drinks and fruit juices can lead to false positives in the Covid-19 lateral flow test but still be negative with a PCR test


So, how can a soft drink cause the appearance of a red T line? One possibility is that the drinks contain something that the antibodies recognise and bind to, just as they do to the virus. But this is rather unlikely. The reason antibodies are used in tests like these is that they are incredibly fussy about what they bind to. There’s all sorts of stuff in the snot and saliva collected by the swabs you take from the nose and mouth, and the antibodies totally ignore this mess of protein, other viruses and remains of your breakfast. So they aren’t going to react to the ingredients of a soft drink.

A much more likely explanation is that something in the drinks is affecting the function of the antibodies. A range of fluids, from fruit juice to cola, have been used to fool the tests, but they all have one thing in common – they are highly acidic. The citric acid in orange juice, phosphoric acid in cola and malic acid in apple juice give these beverages a pH between 2.5 and 4. These are pretty harsh conditions for antibodies, which have evolved to work largely within the bloodstream, with its almost neutral pH of about 7.4.

Even a small change to the chains can dramatically impact a protein’s function


Maintaining an ideal pH for the antibodies is key to the correct function of the test, and that’s the job of the liquid buffer solution that you mix your sample with, provided with the test. The critical role of the buffer is highlighted by the fact that if you mix cola with the buffer – as shown in this debunking of an Australian politician’s claim that mass testing is worthless – then the LFTs behave exactly as you’d expect: negative for Covid-19.

So without the buffer, the antibodies in the test are fully exposed to the acidic pH of the beverages. And this has a dramatic effect on their structure and function. Antibodies are proteins, which are comprised of amino acid building blocks, attached together to form long, linear chains. These chains fold up into very specific structures. Even a small change to the chains can dramatically impact a protein’s function. These structures are maintained by a network of many thousands of interactions between the various parts of the protein. For example, negatively charged parts of a protein will be attracted to positively charged areas.

Many schools in the UK have used regular lateral flow testing to check whether pupils might be carrying the Covid-19 virus


But in acidic conditions, the protein becomes increasingly positively charged. As a result, many of the interactions that hold the protein together are disrupted, the delicate structure of the protein is affected and it no longer functions correctly. In this case, the antibodies’ sensitivity to the virus is lost.

Given this, you might expect that the acidic drinks would result in completely blank tests. But denatured proteins are sticky beasts. All of those perfectly evolved interactions that would normally hold the protein together are now orphaned and looking for something to bind to. A likely explanation is that the immobilised antibodies at the T-line stick directly to the gold particles as they pass by, producing the notorious cola-induced false positive result.

Is there then a way to spot a fake positive test? The antibodies (like most proteins) are capable of refolding and regaining their function when they are returned to more favourable conditions. So I tried washing a test that had been dripped with cola with buffer solution, and sure enough the immobilised antibodies at the T-line regained normal function and released the gold particles, revealing the true negative result on the test.

Children, I applaud your ingenuity, but now that I’ve found a way to uncover your trickery I suggest you use your cunning to devise a set of experiments and test my hypothesis. Then we can publish your results in a peer-reviewed journal.

Newsletter

Related Articles

Beautiful Virgin Islands
0:00
0:00
Close
Explosions Rock Doha as Iranian Missiles Target Qatar
“You Have 12 Hours to Flee”: Israeli Threat Campaign Targets Surviving Iranian Officials
Macron and Merz: Europe must arm itself in an unstable world
Germany and Italy Under Pressure to Repatriate $245bn of Gold from US Vaults
Airlines Evaluate Flight Cancellations Amid Escalating US-Iran Tensions
Starmer Invites Innovators to Join Government Talent Scheme
UK Economy’s Strong Opening Quarter Shows Signs of Cooling
Harrods Seeks Court Order to Secure Al Fayed Estate for Victims
BA and Singapore Airlines Cancel Dubai Flights Amid Middle East Tensions
Trump Faces Backlash from MAGA Base Over Iran Strikes
Meta Bets $14 B on Alexandr Wang to Drive AI Ambitions
WATCH: Israeli forces show the aftermath of a massive airstrike at Iran's Isfahan nuclear site
FedEx Founder Fred Smith, ‘Heart and Soul’ of the Company, Dies at 80
Chinese Factories Shift Away from U.S. Amid Trump‑Era Tariffs
Pimco Seizes Opportunity in Japan’s Dislocated Bond Market
Labubu Doll Drives Pop Mart to Status as China’s Most Valuable Toy Maker
Global Coal Demand Defies Paris Accord Goals
We have new information and breaking details to share about what is shaping up to be a historic air campaign tonight
Six Massive Bombs Dropped on Fordow; Trump: 'A Historic Moment for the U.S., Israel, and the World'
Fordow: Deeply Buried Iranian Enrichment Site in U.S.–Israel Crosshairs
United States Conducts Precision Strikes on Iran’s Nuclear Sites
US strikes Iran nuclear sites, Trump says
Pakistan to nominate Trump for Nobel Peace Prize.
BBC Demands Perplexity AI Immediately Stop Using Its Content
Telegram Founder: I Will Leave My Fortune to Over 100 of My Children
Political Turmoil Resurfaces in Belgium Amid Economic Concerns
Fed policymakers divided on timing of interest rate cuts
Trump signals imminent agreement with Harvard University
Inheritance tax referendum alarms Swiss billionaire community
Japan cancels bilateral security meeting amid US defence demands
AI skeptic Emily Bender warns that ‘the emperor has no clothes’
Israel Confirms Assassination of Quds Force Commander in Tehran
16 Billion Login Credentials Leaked in Unprecedented Cybersecurity Breach
Senate hearing on who was 'really running' Biden White House kicks off
Iranian Military Officers Reportedly Seek Contact with Reza Pahlavi, Signal Intent to Defect
FBI and Senate Investigate Allegations of Chinese Plot to Influence the 2020 Election in Biden’s Favor Using Fake U.S. Driver’s Licenses
Vietnam Emerges as Luxury Yacht Destination for Ultra‑Rich
Plans to Sell Dutch Embassy in Bangkok Face Local Opposition
China's Iranian Oil Imports Face Disruption Amid Escalating Middle East Tensions
Trump's $5 Million 'Trump Card' Visa Program Draws Nearly 70,000 Applicants
DGCA Finds No Major Safety Concerns in Air India's Boeing 787 Fleet
Airlines Reroute Flights Amid Expanding Middle East Conflict Zones
Elon Musk's xAI Seeks $9.3 Billion in Funding Amid AI Expansion
Trump Demands Iran's Unconditional Surrender Amid Escalating Conflict
Israeli Airstrike Targets Iranian State TV in Central Tehran
President Trump is leaving the G7 summit early and has ordered the National Security Council to the Situation Room
Taiwan Imposes Export Ban on Chips to Huawei and SMIC
Israel has just announced plans to strike Tehran again, and in response, Trump has urged people to evacuate
Netanyahu Signals Potential Regime Change in Iran
Juncker Criticizes EU Inaction on Trump Tariffs
×