Feluda: the revolutionary paper-based testing kit for COVID19

Everybody today is waiting for some way to return to the old-normal, pre-COVID world. The only hope for the end of the pandemic seems to be a vaccine that; doesn’t appear to be coming anytime soon. But another way through which normalcy can be attained might be in the market soon; in form of the new paper-testing kit for the virus.

So, what is the Feluda testing kit? How does the paper-based testing kit work? and how can it help the world to achieve a sense of normalcy?

What is Feluda testing kit?

A team of research scientists from the Council of Scientific and Industrial Research (CSIR) in India New Delhi; has developed a new way to test COVID19. The testing kit is named ‘Feluda‘ after a prominent fictional Indian detective Feluda by cinematographer Satyajit Ray. Full name of the paper-strip-based testing kit is Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) Feluda test.

This kit is the world’s first paper-strip-based COVID-19 testing kit and would be a quicker, easier and inexpensive way of testing coronavirus. Every kit would cost INR 500 (approximately $6.75; £5.25).

Feluda was first tested on 2,000 patients some of which were already infected by the virus. The results divulged that the new testing kit has 96% sensitivity and 98% specificity.

  • Sensitivity: the ability of a test to gives true positive results; i.e. the infected person, tests positive for the infection.
  • Specificity: the ability of a test to set out true negative results; i.e. the infection-free person, tests negative for the infection.

These are the two prime benchmarks’ that decide whether the test is reliable or not. Seeing the outcomes of Feluda, Drug Controller General of India (DCGI) have provided the kit sanction for commercial launch; as per the directions of Indian Council of Medical Research (ICMR).

Dr Stephen Kissler, a researcher at Harvard Medical School says; “Testing remains a limited resource and something that we need to do everything we can to improve its availability. So Feluda is an important step in that direction.”

How does the paper-based testing kit work?

Until now, India is using two testing procedures for testing SARS-CoV-2 virus. First is the Polymerase Chain Reaction/ PCR swab test, which employs chemicals for detecting the virus’s genetic material in labs. It costs INR 2,400, is reliable but the drawback is it takes a lot of time and can only be done in labs.

The other one is Speedy Antigen Test, this shows the result by locating fragments of virus in the taken sample. In comparison to PCR, it takes a lot less time and shows precession is a true-positive result but generates a sizeable false-negative result.

CRISPR Feluda test on the other hand uses a completely new method for testing the presence of the virus in the sample. It employs a peculiarly refashioned Cas9 protein to detect SARS-CoV-2 virus and is made via gene-editing technology. Gene-editing is used usually for averting infections and treating minor diseases.

Testing COVID19 with Feluda

In Feluda, the kit contains a gene of the novel coronavirus; when it finds the same gene in the sample it shows the result positive; otherwise, the negative result is highlighted on the read-out paper.

Taking samples for Feluda will be same as for the PCR test. The sample will be taken by inserting a nasal swab a few inches inside the nasal cavity. The sample can also be taken from saliva, but India still does not allow testing COVID19 from saliva.

The testing kit is markedly familiar to self-assessing pregnancy test kits in the market. If a given sample contains the virus the paper indicates two blue lines; if the result is negative a single blue light is highlighted.

A molecular scientist with CSIR-IGBMR and member of the team that developed Feluda, Dr Debojyoti Chakraborty says; “you can extract and amplify the RNA using PCR machine at home. We are trying for a simple, affordable, and truly point-of-care test; so widespread testing is not limited by machines and manpower.”

The need of the hour

Other than India researchers from several parts of the US and the UK are trying to make similar paper-strip-based COVID19 testing kit. One of which developed by Sherlock Bioscience has been sanctioned to be used for emergency purposes by the US Food and Drug Administration (FDA).

India is currently the second worst-hit country by the COVID-19 pandemic. Till now the country has witnessed more than 6.69 million cases, amongst which 5.66 million have successfully recovered but at the same time more than 100,000 people have lost their lives. Globally coronavirus has infected more than 35.5 million people and has led more than 1 million people to death.

A vaccine to this contagious virus is undeniably crucial today but it will still take some more time for it to be available in the market. Recovering from the pandemic is important and until we have the vaccine reliable, accessible testing is also key to achieve a sense of normalcy; says Dr Stephen Kissler.