‘Game-Changing’ Paper-based COVID test named after Satyajit Ray’s Feluda

A team of scientists from IGIB, New Delhi, India developed a paper based COVID test to detect COVID-19. The test is named after Satyajit Ray’s famous detective character called Feluda. This paper-based COVID test is based on a gene-editing technology called CRISPR (Clustered regularly interspaced short palindromic repeats).

This paper based COVID test is designed by a team led by two Bengali-origin scientists, Dr. Souvik Maiti and Dr. Debojyoti Chakraborty, at the Council of Scientific & Industrial Research Institute of Genomics and Integrative Biology (CSIR-IGIB) in New Delhi. It is being commercialized by the Tata Group.


team behind feludsa: paper based covid test CRISPR tata
The team behind Feluda: paper based COVID test: (Left to right) Dr. Debojyoti Chakraborty, Dr. Souvik Maiti, Rhythm Phutela, Mohd Azhar, and Manoj Kumar have worked around the clock to produce the rapid paper-strip test kit   –  IMAGE COURTESY: Dr. Debyajyothi Chakraborty

Some of the key features of CRISPR Feluda paper based COVID test:

  • Gives us results within an hour and costs about 500 rupees.
  • India’s first CRISPR based COVID test.
  • World’s first diagnostic test to deploy a specially adapted Cas9 protein to successfully detect the virus causing Covid-19
  • From R&D to a high-accuracy, scalable and reliable test in less than 100 days
  • 96% sensitivity and 98% specificity for detecting the novel coronavirus.
  • Futuristic technology that can help detect multiple other pathogens in the future.
  • Paper based COVID test is more Cost-effective and faster than traditional RT PCR.

Feluda kits will be made by India’s leading conglomerate Tata. If everything goes as planned this could be the world’s first paper-based covid test in the market.

Understanding Specificity and Sensitivity.

Feluda, CRISPR paper-based COVID test has a sensitivity of 96% and a specificity of 98% for detecting the novel coronavirus.

A higher sensitivity indicates that test detects almost everyone who is infected with COVID. This means that a test with higher sensitivity ensures that we do not get too many false negative results.

Higher specificity indicates that the test can rule out if the person doesn’t have coronavirus infection. This means that test doesn’t give us too many false positive results.

Approval from DCGI

Tata has got an approval from Drugs Controller General of India (DCGI) to manufacture on a commercial scale and for commercial use.

CSIR shared this news on twitter:

People’s Reactions about Feluda: CRISPR Paper-based COVID test

Director general of CSIR, Dr. Shekhar Mande congratulated the team involved in the designing of this test.

Tata group shared a post on twitter about Feluda:

Tata CRISPR test, powered by CSIR and IGIB, is the world’s first diagnostic test to deploy a specially adapted Cas9 protein to successfully detect the virus.

Watch the full talk by Dr. Souvik Maiti here on YouTube:

How does this paper-based COVID test exactly work?

Through a nasal swab, we get RNA samples of the virus from the patient. We first convert this RNA into genetic material or complementary DNA (cDNA). Then we amplify it using a polymerase chain reaction (done on a simple PCR machine) and mix with a complex Cas9 protein. The Cas9 protein specifically binds to the DNA signature of the Covid-19 virus. Finally, this mixture is applied to a paper strip. Depending on the presence of Covid-19 DNA, a line appears on the paper strip, apart from a control line that appears regardless of whether the virus is present or not.

As stated by the team behind Feluda

If there is the presence of even low amounts of viral RNA, it will detect it. The results are known within 1.5 hours. When we scale production of the testing kits, it could be even faster. This is a qualitative test, so it can tell you presence or absence rapidly, but if you want more quantitative data then you can always do that with a more sensitive RT-PCR technique.

Why did they name the test ‘Feluda’?

Dr. Chakraborty revealed why they named it Feluda:

The reason we named it ‘Feluda’ was because a competitive paper-strip test being developed by MIT and Harvard goes by the name ‘Sherlock’, after the famous [fictional] detective. So we wanted to give it an Indian twist and decided to call it ‘Feluda’, after Bengal’s most famous detective character created by Satyajit Ray. Also ‘Feluda’ is an acronym for the scientific name of the test — Fncas9 Editor Linked Uniform Detection Assay.

Read the press release by PIB: Click here:

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