COVID testing is key to fighting the pandemic, allowing individuals to know their infection status and informing us about the spread of the virus. However, the time it takes to run lab tests forms a bottleneck, reducing the testing capacity of labs and meaning that some people have to isolate for days before knowing if they are infected. Quick antibody tests are available, but are less accurate and cannot be used to diagnose current infections. In a preprint paper (yet to be peer-reviewed) published on MedRxiv, researchers from the University of Birmingham have developed a speedier option called EXPAR, which could be the best of both worlds.
Speaking to IFLScience, co-author of the study and Professor of Biotechnology at the University of Birmingham Tim Dafforn explained, “Testing for COVID-19 takes two forms. Central laboratories use a test (commonly called the PCR test) that detects the genes of the virus. These tests are very accurate but generally have to be carried out in laboratories. The second type of test is the lateral flow, or dipstick test (the one that looks like a pregnancy test). This test can be carried out in the community with minimum training but is in general less accurate. Both tests take >30 minutes, which means neither are useful where large numbers of people need to be tested quickly (eg at an airport). Our test detects the genes of the virus, like the PCR test, but is simpler, like the lateral flow test.”
Professor Dafforn goes on to describe how the new test works: “We have managed this by altering the way we do the PCR test. This test normally has two steps, the first takes up to 20 minutes, the second up to 90. We have invented a new way to do the first stage called RTF so it now takes less than 30 seconds and added it to a very rapid version of the second stage called EXPAR to produce a test that takes only 5 minutes. We combined both stages into a single pot making the whole test much simpler.”
This development could have a big impact on testing. Quick results could help industries that require being inside – retail, traveling, the entertainment industry etc – towards getting back on their feet.
“This jump in assay speed means that in the short term more than 5 times the tests can be carried out in laboratories than using the existing methods," Professor Dafforn said. "In the future, the simplicity and speed of the test mean that it could be deployed at ports of entry, airports, and even entertainment venues to ensure that people are virus-free.”
The paper is a preprint, which means it is yet to go through peer review. However, the results are promising. The new test is incredibly speedy, can be performed on standard lab equipment, and does not require sample treatment at high temperatures like in PCR. “The EXPAR technique has been tried and tested over several years, but we’ve been able to apply it in a new way to detect COVID-19," said co-author Professor Jim Tucker from the University of Birmingham School of Chemistry in a statement. "This is an extremely promising approach to developing a rapid, accurate test which could increase NHS testing capability by up to five times.”
This EXPAR test was developed specifically in response to the COVID-19 pandemic, however, it could have wider applications. In the future, this testing method could be used for other viruses, bacteria, and even cancer.