British scientists have developed a new diagnostic test for COVID-19 that gives the result in 10 minutes

Researchers at the University of Birmingham have presented a coronavirus diagnostic kit that gives a result in less than 10 minutes, at the same time that they emphasized the speed, precision and simplicity of the test method, which they described as new and very sensitive for COVID-19, “which can be deployed in entertainment venues, airport arrival terminals and in remote environments where clinical trial laboratories are not available”.

Scientists used a three-pronged comparative study to confirm that the exponential amplification reaction (EXPAR) method is as sensitive, but faster, than the PCR and LAMP tests currently in use in a hospital environment. The Birmingham COVID-19 test, called RTF-EXPAR, gives a sample-signal time of less than 10 minutes, even for low viral levels where current lateral flow tests are less effective.

Teachers The Dafforn team from the Faculty of Biosciences, expert engineer in biophysical spectroscopy with a great interest in synthetic biology and Jim tucker from the Faculty of Chemistry, a chemist specializing in the design and study of supramolecular systems and functional DNA-based assemblies, collaborated with Professor Andrew Beggs of the Institute of Cancer and Genomic Sciences of the to study, which was published today in the scientific journal Proceedings of the National Academy of Sciences ( PNAS, for its acronyms in English). it’s about the Official publication of the United States National Academy of Sciences.

Both PCR and LAMP tests detect viral RNA, which can be present at extremely low levels in swabs taken from the mouth and nose. These tests use a two-step process that involves first converting RNA to DNA (a process called reverse transcription) and then “amplifying” the material multiple times so that it can be detected in the sample.

Technically, the assay is an exponential amplification reaction assay without reverse transcriptase as accurate as the PCR and LAMP currently in use.

Professor Dafforn clarified: “The reverse transcription and amplification steps slow down existing COVID tests that rely on nucleic acid detection, compared to antigen tests, such as lateral flow, which do not have these steps. However, while this makes lateral flow tests faster than those based on PCR and LAMP, they are often less sensitive in return. An ideal test would be a sufficiently sensitive and rapid test; our test, called RTF-EXPAR, achieves this objective ”.

RTF-EXPAR achieves this feat in two ways: The test team designed a new RNA-to-DNA conversion step that prevents reverse transcription, rendering it without reverse transcription (RTF). Second, its amplification step to generate the read signal uses EXPAR, an alternative DNA amplification method to PCR and LAMP.

Professor Dafforn added: “EXPAR amplifies DNA at a single temperature, thus avoiding the long heating and cooling steps found in PCR. However, while LAMP also uses a single temperature for amplification, EXPAR is a simpler and more straightforward process., in which much smaller strings are amplified. This makes EXPAR an even faster DNA amplification technique than not only PCR but also LAMP ”.

The study revealed that the RTF-EXPAR method converts less than 10 strands of RNA into billions of DNA copies in less than 10 minutes, using a single pot test compatible with more basic benchtop equipment than that used with current test methods.

RTF-EXPAR also demonstrated significant improvements over PCR and LAMP tests over time for signal detection. Identification of the optimal sequence was clearly an important step in the development of the EXPAR method, and the sequence detected in the study, in the SARS-CoV-2 genome, it has been shown to be preserved at all current levels. COVID-19 variants. However, the RTF-EXPAR method can be adapted quickly in the event of the emergence of new variants or to test other viral pathogens such as influenza, respiratory syncytial virus (RSV) or Ebola, or tests on close patients. are necessary to avoid a more extensive transmission.

The test was tested at the Surgical Research Laboratory at the University of Birmingham. Andrew Beggs, whose team performed the tests, commented: “The tests used swabs that contained a typical range of viral loads seen during the pandemic and had a cut-off time of six minutes.. The analysis showed that the sensitivity of RTF-EXPAR is equivalent to the quantitative PCR test, with a positive predictive value of 89% and a negative predictive value of 93%.. We hope to publish the full results of these tests in the near future. “

The research group is now looking for business partners to obtain quick licenses for the soon to be released diagnostic kit.

The Birmingham University was founded on March 24, 1900 by Victoria I of the United Kingdom and It is, with 27,000 students, the largest university in the English metropolis of Birmingham and also one of the largest in all of England..

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