New York: A team of scientists has developed a new portable, pocket-sized machine that can diagnose SARS-CoV-2, the virus that causes Covid-19, in just 15 minutes. Globally, Covid-19 has infected nearly 129 million people and claimed 2.81 million lives.
The new test -- NIRVANA -- can produce positive and negative results of 96 samples of Covid-19, influenza A, human adenovirus, and non-SARS-CoV-2 human coronavirus -- in real time. And within three hours, it can track new variants such as the B.1.1.7, identified in the UK, revealed the study published in the journal Med.
The NIRVANA test uses a gene-detection approach called isothermal recombinase polymerase amplification (RPA) that is coupled with real-time nanopore sequencing. It is cheaper and more portable than the current Covid-19 testing approach -- a polymerase chain reaction (PCR) test, done via nasal swab.
While the PCR test cycles through lower and higher temperatures to separate DNA strands and copy them, the RPA, uses proteins to accomplish the same thing in just 20 minutes. Further, the PCR test requires expensive next-generation gene-sequencing machine to detect other viruses, but, RPS can diagnose multiple genes at the same time.
"We quickly realised that we could use this technique to not only detect SARS-CoV-2, but other viruses at the same time," according to Mo Li, an assistant professor of bioscience at King Abdullah University of Science and Technology in Saudi Arabia.
The device can be installed at schools, airports or ports, for faster detection of Covid-19 viruses, the researchers suggested. Alternatvely, the device can be used to monitor wastewater or streams for the presence of new viruses.
For the study, the team tested NIRVANA on 10 samples known to be positive for SARS-CoV-2, 60 samples of unknown SARS-CoV-2 status, as well as samples of municipal wastewater harbouring the SARS-COV-2 virus and others.
In all cases, it correctly identified the viruses present, and the sequencing data narrowed down the origin of SARS-CoV-2 in positive samples; differentiating strains from China and Europe, for instance.