Kingston upon Hull, UK - A professor of chemistry has figured out how kids have been getting false positives on Covid-19 tests in order to stay home from school and offers parents a way to check for the trick.

As first reported by The Conversation, Mark Lorch, Professor of Science Communication and Chemistry at the University of Hull, heard the rumors that kids had been faking positive Covid-19 tests in order to get out of school.

He decided to figure out the science that made their attempts work, and how to check whether a result was genuine or not.

The tests in question are lateral flow tests, or LFTs, which are antigen tests you can do at home yourself. LFT's work by identifying specific molecules – antigens – which are present on the outside of the coronavirus that causes Covid-19.

Professor Lorch tested some of the LFTs with different substances instead of saliva, as should normally be used, to see how the tests reacted. Apparently, for parents or school admin who didn't know any better, these tests were actually insanely easy to trick.

He determined that, instead of using the liquid provided with the tests, using a few drops of a very acidic soft drink or juice will trick the antibodies into thinking they were binding to the actual virus. Next thing you know, you have a positive test.

Fortunately for parents, Lorch says that checking for the trick is simple. By taking the buffer solution that comes with the test and using it to rinse off the port onto which the sample has been dripped, the antibodies will effectively be reset, showing a true result.

Better luck next time, kids!