Speed and maximum precision of test to diagnose infection with coronavirus SARS-CoV-2 these are two fundamental parameters, but they hardly go hand in hand. A new test in development, however, promises to combine the effectiveness of the best diagnostic kits with a significantly higher speed than that of the so-called quick swabs. As we know, the most effective test ever after a tampone oro-rinofaringeo and the RT-PCR (reverse polymerase chain reaction), a molecular assay that amplifies theViral RNA present in the biological sample extracted from the patient and which requires sophisticated laboratory instrumentation, especially to reach the high temperatures at the base of the process. It can take up to 48 hours to get the results of such a test, for example after switching to the drive-in, due to logistical issues. The rapid antigenic tests that hunt for the superficial proteins of the virus and not its genome, on the other hand, give a much faster response (between 15 and 30 minutes), but they are not true diagnostic tests in clinical setting – unlike RT-PCR – and are considered less accurate, with a higher risk of false positives–negatives. It is no coincidence that those who test positive for the quick swab must then undergo the classic one. Now, thanks to a new ultra-rapid test being tested, it will be possible to obtain a response in less than 5 minutes and with the same precision as RT-PCR, thanks to the refined technology on which it is based.
The new diagnostic kit was developed by an interdisciplinary research team from the University of Birmingham, made up of experts from the School of Biological Sciences, the School of Chemistry and the Institute on Cancer and Genomic Sciences. Research on the test – funded by the Midlands Integrative Biosciences Training Partnership (MIBTP) – was conducted using patient-extracted viral RNA samples provided by Public Health England. The kit is based on technology EXPAR (Exponential Amplification Reaction) capable of shortening the times and reducing the two necessary for RT-PCR to a single phase. In molecular testin fact, in the first phase the conversion of RNA into DNA, while in the second the amplification of the genetic material is carried out numerous times, as indicated in a Press release of the British university. Thanks to the EXPAR technique, “very short, single strands of DNA are used for the replication process, which can be completed in minutes, significantly reducing the overall time required to obtain results”. The entire procedure for hunting down the genetic material of SARS-CoV-2 can be performed on standard laboratory equipment and at significantly lower temperatures than RT-PCR, which requires high heat “to separate the DNA strands as part of the process. amplification “. The procedure is therefore able to give a response in a very short time and with maximum diagnostic effectiveness.
Thanks to special kits being designed, as specified by Professor Tim Dafforn, a test of this type can be used at the entrance of shopping centers, airports, stations and other public places in order to obtain very rapid results with the utmost precision, with the certainty of guaranteeing access to people free from the SARS-CoV-2 coronavirus. “. “The EXPAR technique has been tried and tested for several years, but we have been able to apply it in a new way to detect the COVID-19. This is an extremely promising approach to developing a rapid and accurate test that could increase NHS testing capacity by up to five times “, he has declared Professor Jim Tucker. The new test was described in the article “Sub-5-minute Detection of SARS-CoV-2 RNA using a Reverse Transcriptase-Free Exponential Amplification Reaction, RTF-EXPAR”, Available on the MedrXiv online database and awaiting peer review for publication in a scientific journal.