The Feluda test is priced at Rs 500 and can give a result in 45 minutes. (Representative)
New Delhi:
More accurate than a rapid antigen test and almost as fast, India’s CRISPR ‘Feluda’ COVID-19 test which changes color upon detection of the SARS-CoV-2 virus could be a cheaper alternative, faster and easier to diagnose from RT-PCR, say scientists.
Named after the famous detective of Satyajit Ray, the Feluda test, which is priced at Rs 500 and can give a result in 45 minutes, is able to differentiate SARS-CoV-2 from other coronaviruses even if the genetic variations between they are tiny.
The Feluda Regularly Interrupted Clustered Short Palindromic Repeat (CRISPR) test, developed by the CSIR-Institute of Genomics and Integrative Biology (IGIB) in New Delhi and the TATA Group, received regulatory approvals from the Drug Controller General of India (DCGI). ) for commercial launch.
It meets high-quality criteria with a sensitivity of 96% and a specificity of 98% for the detection of the novel coronavirus, told PTI Debojyoti Chakraborty, a senior scientist at CSIR-IGIB and part of the team that has developed the test.
In any diagnosis, sensitivity is defined as the ability of a test to correctly identify people with the disease, while specificity is the ability of the test to accurately identify those who do not have the disease.
Similar to a pregnancy strip test, Feluda changes color if the virus is detected and does not need expensive machines for detection.
“CRISPR technology uses a highly specific CAS9 protein to find and bind to the target COVID signature. This is then coupled with the chemistry of the paper strip to get a visual reading on a paper strip,” explained Mr. Chakraborty .
The test may help the country, with the world‘s second-largest COVID-19 case at 60.74 lakh cases, speed up testing for the disease quickly and economically, the researchers behind the test said in a statement .
Virologist Upasana Ray noted that the CRISPR-based COVID-19 detection system is a cheaper option than RT-PCR tests, which cost more than Rs 1,600. The RAT and the Feluda are in the same price bracket.
FELUDA, acronym for FNCAS9 Editor-Limited Uniform Detection Assay, uses state-of-the-art CRISPR technology developed locally for the detection of the genomic sequence of the SARS-CoV-2 virus, the scientists said.
CRISPR is a gene editing technology and is used to correct genetic defects and to treat and prevent the spread of disease.
The technology can detect specific sequences of DNA in a gene and uses an enzyme that works like molecular scissors to cut it.
According to Mr Ray, Feluda is able to detect even small amounts of genetic material from the novel coronavirus, based on very tiny differences in their RNA – the genetic material of a virus.
“Feluda is an alternative to quantitative RT-PCR assays and is very specific. It is able to detect nucleic acids with low copy number (less amount of viral RNA) as well as variations of single nucleotides”, Mr. Ray, senior researcher at CSIR-IICB, Kolkata, told PTI.
She explained that the tests are so specific that they can distinguish SARS-CoV-2 infections from other coronaviruses such as the one that caused the 2002-03 SARS pandemic.
“It can distinguish between SARS-CoV-2 and SARS-CoV sequences which differ by a single nucleotide. Unlike RT-PCR which requires expensive machines, Feluda is simple and can be used in laboratories as well as in outside with a faster turnaround time, ”she added.
In May, the United States granted emergency use authorization for the world‘s first CRISPR test for COVID-19, developed by the Massachusetts Institute of Technology (MIT) and Harvard University.
The CRISPR Feluda test is the world‘s first diagnostic test to deploy a specially adapted Cas9 protein, derived from the bacteria Francisella novicida, to successfully detect the virus responsible for COVID-19, the researchers said.
Other CRISPR ™ tests, such as the one developed in the United States, use the CAS12 and CAS13 proteins to detect SARS-CoV-2.
Compared to a rapid antigen test, which interprets results in 30 minutes, Mr Ray said the Feluda test would take a little longer, up to 45 minutes, but it is more precise and specific.
Rapid antigen tests detect viral proteins or parts of them, while CRISPR detects nucleic acids, or RNA in the case of COVID-19, Ray said.
Chakaraborty noted that RT-PCR takes about 1.5 hours, a trained workforce, and a dedicated and expensive RT-PCR machine that is not widely available.
“Feluda offers similar sensitivity and specificity to RT-PCR, but it is inexpensive, requires a widely available basic PCR machine, and does not require a trained workforce. Chemistry and biology are of course different “, added Mr. Chakraborty.
“This marks a significant achievement for the Indian scientific community, moving from R&D to high-precision, scalable and reliable testing in less than 100 days. The Tata CRISPR assay achieves precision levels of traditional RT-PCR assays, with faster turnaround time, cheaper equipment and better ease of use, ”the researchers said in their release.
They described CRISPR as a futuristic technology that can also be configured for the detection of other pathogens in the future.
“Current R&D aims to make Feluda more point of service, simpler and more deployable to meet the testing needs of the country and allow return to workplaces, schools, etc.”, added Mr. Chakraborty.
(Except for the title, this story was not edited by GalacticGaming staff and is posted from a syndicated feed.)
