A new corona test detects viral DNA in minutes – know
Scientists report an idea feasibility study in the scientific journal Nano where they describe the development of a more accurate diagnostic test based on plasmonic photothermal sensing.
[תרגום מאת ד”ר משה נחמני]
Millions of people have already been tested for the new corona virus, with most of them using a test kit that relies on the Polymerase Chain Reaction (PCR) method. This sensitive method increases the amount of RNA of the new virus (SARS-CoV-2) taken from the throat surfaces or even of subjects so that even tiny amounts of the virus can be detected.
However, as the global pandemic spreads, this “workhorse” found in labs shows signs of burnout. Scientists are now reporting an idea feasibility study in the scientific journal Nano where they describe the development of a more accurate diagnostic test based on plasmonic photothermal sensing. Medical experts agree that speeding up tests is a critical step in controlling the spread of the infectious virus. However, the rate and volume of tests in many countries, including the US, are in serious disarray, due to limited supply of certain reagents and accumulation of samples waiting for available PCR devices and trained laboratory workers. In addition, many cases of false negative / positive test results have been reported. Other methods, such as computed tomographic scan (CT), do not provide fast or real-time results, and US researcher Jing Wang and her research team have been able to develop a faster and more accurate test for the presence of the corona virus, a test that could be a viable alternative to PCR testing.
The researchers based their research on a method called localized surface plasmon resonance, which is able to detect interactions between molecules located on the surface of a metallic nanoparticle as a local modification of the refractive index. The researchers developed a DNA detector that identifies defined sequences of SARS-CoV-2 RNA and binds them to gold nanoparticles. When sections of the virus genome are added, the detector-bound RNA segments bind to their complementary segments and simulate a situation similar to a zipper closure. The results of ‘false positives’, for example, a ‘zipper’ of nucleic acids lacking a pair of acids – evidence of structural mismatch – will not remain connected under these conditions, allowing researchers to differentiate between the two strains of the corona virus: SARS-CoV- 2 in the face of SARS-CoV-1. Researchers’ innovative biological test has been able to detect quantities of viral RNA found in mucous membranes in And some minutes. Although test efficacy and reliability still need to be tested in real viral RNA taken from patient samples, researchers say it will be able to reduce the current load of PCR-based testing.