New study suggests SARS-CoV-2 may be detected using a ‘naked eye’ test. What is a naked eye test? Elaborate. Why is is better than the conventional RT-PCR test?
Scientists at the University of Maryland School of Medicine (UMSOM) have developed an experimental diagnostic test for COVID-19 that can visually detect the presence of SARS-CoV-2 in 10 minutes.
The development comes as the number of cases of the virus continues to rise even as governments of many countries have started loosening restrictions on their residents.
With relatively free movement, the chances of the infection spreading are greater and therefore, tests that can deliver results as quickly, like this naked eye test, may be crucial in containing the spread of the disease.
The test uses a highly specific molecule that attaches itself to gold nanoparticles, which is able to detect a specific protein, which is a part of the genetic sequence unique to the virus.
Through this “naked eye” test, a nasal swab or a saliva sample is taken from the patient and mixed with a simple laboratory test, which contains a liquid mixed with gold nanoparticles attached to a molecule that binds itself to SARS-CoV-2.
If the solution turns to a deep blue colour, it indicates that the virus is present. On the other hand, if the solution does not contain the virus in it, it does not change its colour and retains its purple hue.
This method is faster than other tests such as the conventional RT-PCR test since it does not require the use of advanced laboratory techniques, which is the case with techniques commonly used to amplify DNA for analysis.
In the PCR test for instance, the RNA of the SARS-CoV-2 virus is first converted into DNA using a process called reverse transcription after which copies of the DNA are made and amplified.
RT-PCR tests can take up to nine hours to show results, however, the overall time, from the time that the samples are collected to the report being delivered can take over 24 hours.
Further, while rapid tests and RT-PCR tests are capable of delivering false negative results, the chances of that happening with the naked eye test are low.
Moreover, because this test does not require laboratory equipment or trained personnel to run the test and analyse the results, it could be far less expensive than the other tests available in the market.