Corona Daily 037: A Glass of Useful Orange Juice

In the UK, many school children are testing positive and missing schools.

UK has made testing easy and less expensive. The lateral-flow tests, rapid antigen tests, were known earlier for their common use in pregnancy testing. In that test, they detect presence or absence of a hormone in a woman’s urine. The simple device can also analyse other body fluids like blood or saliva.

To detect covid-19, one can take the sample of mucus from the nose or throat using a swab. This can be done at home. The sample is then mixed with the liquid solution given as part of the test. The diluted sample is placed at the end of a porous strip in a cartridge. The strip has a line of antibodies. As soon as those antibodies recognize the presence of the covid-19 virus, they cling to it. Just like a positive pregnancy test, a coloured band appears on the strip to indicate a covid-19 infection.

The tests are speedy and simple. Results are ready within fifteen minutes. The more common PCR tests look for the virus’s genetic sequence, these tests don’t. For a soccer match or a stadium concert, such tests can be done at the entrance. They are good at catching highly infectious individuals.

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Every school in the world has children who dislike going to school. Particularly, after staying at home for more than a year, it is a shock for some to restart hectic school life.

Some British children, perhaps with a scientific bend of mind tried different experiments. These were inspired by TikTok videos. They used fresh orange juice, coca-cola and other fizzy drinks and found they were getting a “positive red”. Delighted, they produced the results of tests done at home. In some schools, the bubble policy sent the entire class home.

Children, not aware of the government regulations, realized their quarantine and joy were short-lived. UK government requires that anybody producing a positive result in a rapid test must undergo a more robust PCR test in a lab for confirmatory result.

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Mark Lorch is a chemistry professor at the University of Hull. He read about this epidemic of fake positive tests. He had also seen an Austrian politician performing a Coca-cola positive test in the Austrian parliament to claim that those rapid antigen tests were worthless.

Professor Lorch decided to find out for himself. First, he tested with bottles of cola and orange juice. Just like the school children, he was able to get the red lines.

Antibodies are incredibly discerning. The sample collected by the swabs includes all sorts of things. Antibodies, focused on the virus, ignore them all. So why were they reacting to the ingredients of a soft drink, wondered the professor.

The most likely explanation was that something in the drinks was affecting the function of the antibodies. Fruit juices and colas were both strongly acidic. In these harsh conditions, antibodies were unable to function.

In fact, the liquid solution that comes as part of the kit serves to maintain the functioning of antibodies. What the school children and the Austrian politician had done was to not use the liquid solution at all.

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Professor Lorch knew antibodies are capable of regaining their functionality under the right conditions. He took a “positive” test with cola and washed it with the liquid solution. The immobilized antibodies functioned again, and gave a negative test result. It was like washing away the school children’s sins.

The professor has applauded the ingenuity of the truant schoolchildren. He has requested them to test his hypothesis by carrying out experiments. He promises to publish the results in a peer-reviewed scientific journal.

Ravi