Researchers in the UK have developed a rapid COVID-19 test with the ability to give accurate results within minutes.
Currently, the gold-standard for detecting coronavirus is the reverse transcriptase-polymerase chain reaction (RT-PCR) technique. However, this two-step process can take over 60 minutes per sample. The viral RNA is first converted to DNA and then it undergoes amplification. The amplification process usually requires varying temperature cycles and can take up to an hour. Therefore, scientists have developed multiple rapid COVID-19 tests with shorter sample processing times. However, none have been able to give results in under 20 minutes.
Now for the first time, researchers have developed a diagnostic test that can give accurate results in under five minutes. The team at the University of Birmingham hopes this will reduce detection time and increase the number of samples processed. They described the diagnostic test in a preprint paper published on MedRxiv.
We have designed a new method for testing that combines the ease of use and speed of lateral flow testing with the inherent sensitivity of an RNA test. 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.
Professor Tim Dafforn
Diagnosis in 5 Minutes
The new COVID-19 test employs a single-step method for converting viral RNA to DNA. It then uses an alternative amplification method called EXPAR (Exponential Amplification Reaction). EXPAR gives results within minutes and uses constant, low temperatures. Furthermore, the technique can run on standard laboratory equipment.
Researchers have named the new method Reverse Transcriptase Free EXPAR (RTF-EXPAR) testing.
Although the EXPAR technique has been tried several times in the past, this is the first time it’s being used to detect COVID-19. The team believes further development can likely lead to the production of a handheld test for ‘on the spot’ results.
More rapid testing will allow us to unlock near-patient testing, getting people safely back to work, and controlling outbreaks when they happen. The development of the EXPAR test will allow us to produce more tests that can rapidly diagnose COVID-19
Professor Andrew Beggs
Although the method is specifically for detecting the novel coronavirus, researchers believe that in the future EXPAR can likely help detect other RNA-based viruses and bacteria.
Reference:
Jake G Carter et al. Sub-5-minute Detection of SARS-CoV-2 RNA using a Reverse Transcriptase-Free Exponential Amplification Reaction, RTF-EXPAR, (2021). DOI: 10.1101/2020.12.31.20248236
