IGIB scientists develop low cost COVID-19 test; name it after detective character 'Feluda'

Scientists at the CSIR's Institute of Genomics and Integrative Biology have come up with a low-cost coronavirus test that will not require any expensive machines for the detection of the pathogen. Named after 'Feluda', the detective character in legendary filmmaker Satyajit Ray's stories, the test has been developed by Debojyoti Chakraborty and Souvik Maiti as a simpler way of detecting SARS-coV2 presence in clinical samples, IGIB Director Anurag Agarwal said.

CSIR is a department under the Union Ministry of Science and Technology. It starts the same way as a normal real-time reverse transcription-polymerase chain reaction (RT-PCR), which is the extraction of ribonucleic acid (RNA) and its conversion to deoxyribonucleic acid (DNA), Agarwal said. It then differs by using a specifically designed PCR reaction to amplify a part of the viral nucleic acid sequence. Then a highly specific CRISPR, FnCAS9, developed at IGIB, binds to that sequence, he added. Using the innovative chemistry on a paper strip, the CRISPR complex, bound to that specific sequence, can be visualized as a positive band - like one sees in simple pregnancy tests.

The total time required for the test is less than one hour. In the RT-PCR tests, the RNA is converted to DNA by using specific primers and probes, with fluorescent reporters, to amplify and detect viral nucleic acid presence. It requires expensive Real-Time PCR machines that are available at specialized sites. "If successfully commercialized, which depends upon all its components being available at scale and the commercial product being successfully validated by regulatory agencies, it would allow the test to be done in local path-labs that do not have expensive real-time PCR machines, but simple cheap thermo-blocks used for conventional PCR," Agarwal said.

When asked why the test was named after Feluda, Agarwal said the researchers at MIT and the University of California, Berkeley also use CRSIPR, but different technologies. They have named the tests as 'Detector' and 'Sherlock', so Feluda was an Indian version, he added.