London Daily

Focus on the big picture.
Sunday, Aug 10, 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

0:00
0:00
Close
Street justice isn’t pretty but how else do you deal with this kind of insanity? Sometimes someone needs to standup and say something
Armenia and Azerbaijan sign U.S.-brokered accord at White House outlining transit link via southern Armenia
Barcelona Resolves Captaincy Issue with Marc-André ter Stegen
US Justice Department Seeks Release of Epstein and Maxwell Grand Jury Exhibits Amid Legal and Victim Challenges
Trump Urges Intel CEO Lip-Bu Tan to Resign Over Alleged Chinese Business Ties
Scotland’s First Minister Meets Trump Amid Visit Highlighting Whisky Tariffs, Gaza Crisis and Heritage Links
Trump Administration Increases Reward for Arrest of Venezuelan President Maduro to Fifty Million Dollars
Armenia and Azerbaijan to Sign US-Brokered Framework Agreement for Nakhchivan Corridor
British Labour Government Utilizes Counter-Terrorism Tools for Social Media Monitoring Against Legitimate Critics
OpenAI Launches GPT‑5, Its Most Advanced AI Model Yet
Embarrassment in Britain: Homelessness Minister Evicted Tenants and Forced to Resign
President Trump nominated Stephen Miran, his top economic adviser and a critic of the Federal Reserve, to temporarily fill an open Fed seat
The AI-Powered Education Revolution: Market Potential and Transformative Impact
Chikungunya Virus Outbreak in Southern China: Over 7,000 Hospitalized
French wine makers have seen catastrophic damage to vines that were almost ready to be harvested after the worst fires in more than 70 years burned through the south of the country
US Lawmaker Probes Intel CEO’s China Ties Amid National Security Concerns
Brazilian President Lula says he’ll contact the leaders of BRICS states to propose a unified response to U.S. tariffs
Trump Open to Meeting Putin as Soon as Next Week, with Possible Trilateral Summit Including Zelenskiy
Katy Perry and Justin Trudeau spark dating rumors, joining high stakes world of celeb-politician romances
US envoy Steve Witkoff arrived in Moscow to seek a breakthrough in the Ukraine war ahead of President Trump’s peace deadline
WhatsApp Deletes 6.8 Million Scam Accounts Amid Rising Global Fraud
Nine people have been hospitalized and dozens of salmonella cases have been reported after an outbreak of infections linked to certain brands of pistachios and pistachio-containing products, according to the Public Health Agency of Canada
Karol Nawrocki Inaugurated as Poland’s President, Setting Stage for Clash with Tusk Government
Trump Signals JD Vance as ‘Most Likely’ MAGA Successor for 2028
US Charges Two Chinese Nationals for Illegal Nvidia AI Chip Exports
Texas Residents Face Water Restrictions While AI Data Centers Consume Millions of Gallons
U.S. Tariff Policy Triggers Market Volatility Amid Growing Global Trade Tensions
Tariffs, AI, and the Shifting U.S. Macro Landscape: Navigating a New Economic Regime
Representative Greene Urges H-1B Visa Cuts Amid U.S.-India Trade Tensions
U.S. House Committee Subpoenas Clintons and Senior Officials in Epstein Investigation
Sydney Sweeney Registered as Republican as Controversial American Eagle Ad Sparks Debate
Trump Accuses Major Banks of Politically Motivated Account Denials and Prepares Executive Order
TikTok Removes Huda Kattan Video Over Anti-Israel Conspiracy Claims
Trump Threatens Tariffs on India Over Russian Oil Imports
German Finance Minister Criticizes Trump’s Attacks on Institutions
U.S. Proposes Visa Bond of Up to $15,000 for Some Applicants
U.S. Farmers Increase Lobbying Amid Immigration Crackdown
Elon Musk Receives $23.7 Billion Tesla Stock Award
Texas House Paralyzed After Democrats Walk Out Over Redistricting
Mexican Cartels Complicate Sheinbaum’s U.S. Security Talks
Mark Zuckerberg Declares War on the iPhone
India Rejects U.S. Tariff Threat, Defends Russian Oil Purchases
United States Establishes Strategic Bitcoin Reserve and Digital Asset Stockpile
Thousands of Private ChatGPT Conversations Accidentally Indexed by Google
China Tightens Mineral Controls, Curtailing Critical Inputs for Western Defence Contractors
OpenAI’s Bold Bet: Teaching AI to Think, Not Just Chat
Tesla Seeks Shareholder Approval for $29 Billion Compensation Package for Elon Musk
Nvidia is cutting prices on its RTX 50-series graphics cards after sales slowed and inventories piled up
Ghislaine Maxwell Transferred to Minimum-Security Prison Amid Ongoing DOJ Discussions
U.S. Tariffs Surge to Highest Levels in Nearly a Century Under Second Trump Term
×