Now, you can get COVID-19 test results in less than 5 min

To enable rapid COVID-19 testing, the University of Birmingham researchers have developed a new method called "Reverse Transcriptase Free EXPAR (RTF-EXPAR) testing." Read to know more about this new test.

Do you have to wait for hours to get your COVID-19 test results? It is not just frustrating for the patients, but the delay in realising the test results could lead to more spread of the disease as some people don't show symptoms of COVID-19. Rapid testing and fast results, on the other hand, allows people to know sooner whether they need to isolate to avoid transmitting the virus to others.

Thanks to University of Birmingham researchers, people can now get COVID-19 test results in less than 5 minutes. They have designed a new method for testing that reduces testing time from 30 minutes to under five and delivers accurate results. The new COVID-19 test is described in a preprint paper published on MedRxiv.

The new method for testing combines the ease of use and speed of lateral flow testing with the inherent sensitivity of an RNA test, said Professor Tim Dafforn from the University's School of Biosciences.

It features reagents that can be used in existing point of care devices and meets the need for testing in high throughput, near-patient, settings where people may be waiting in line for their results, he added.

How it is different from the current COVID-19 testing methods?

The Reverse Transcription Polymerase Chain Reaction (RT-PCR) test, which is the current gold standard for COVID-19 testing, takes more than an hour per sample and involves two steps. The first step requires using a reverse transcriptase enzyme to convert RNA to DNA and this normally takes 30 minutes. Then, in second step, a DNA polymerase enzyme is used to copy the DNA and amplify it to detectable levels, which requires time-consuming cycles of heating and cooling. Even single temperature processes have been able to reduce this step below 20 minutes. Antibody tests, which can determine if the person had coronavirus, can take up to 30 minutes.

To enable rapid COVID-19 testing, the University of Birmingham researchers have developed a new method called "Reverse Transcriptase Free EXPAR (RTF-EXPAR) testing." They created a novel single-step approach for converting viral RNA into DNA and combined it with a known technique called Exponential Amplification Reaction (EXPAR), which increases DNA concentration to detectable levels at a constant temperature.

The University of Birmingham Enterprise has reportedly filed a patent for the new method and its use in diagnostic equipment. It is also seeking to license the patent for rapid product development.

Know more about the new RTF-EXPAR testing

According to the researchers, the new testing method uses a DNA sequence (called Binder DNA) that recognises and binds to SARS-CoV-2 viral RNA and an enzyme (BstNI) that recognises the Binder DNA and cuts a short section from it when viral RNA is present. The cycle is repeated as the viral RNA binds to more Binder DNA. The output of this cycle gives the results of the test.

When the researchers tested the method, they got the test results in 4.00 +/- 0.72 minutes for the positive sample. The concentration of SARS-CoV-2 RNA in the positive sample was found to be 72.7 copies/ L, which is up to 10 times lower than the average viral load found in COVID-19 patient samples.

Although the method was developed for COVID-19 testing, it could be applied to any RNA-based infectious agent or disease biomarker, including cancer, they researchers noted.