Feluda gets on the detection train for Covid-19

India's first paper-strip Covid test provides accurate and low-cost testing in less than 30 minutes, and will go a long way in regulating continuous functioning of business.

You will be forgiven if the name Feluda conjures up images of Satyajit Ray's Bengali private eye with an analytical mind and a nose to sniff out the deepest hidden mysteries. The eponymous test, also an acronym for FNCAS9 Editor Linked Uniform Detection Assay, is similiarly designed to sniff out the virus and deliver results in minutes as opposed to the existing RT-PCR kits, which takes anywhere between 4 to 5 hours. In a much needed win for the nation, Feluda has recently been approved by the Drug Controller General of India (DCGI) for a commercial roll out.

What does Feluda do, exactly

The paper-based testing strip developed indigenously by a team of young scientists of the Council of Scientific Industrial Research (CSIR) and Tata uses the CRISPR gene-editing technology to identify and target the genetic material of the Covid (SARS-CoV2) virus.

The test is similar to the mechanism of a pregnancy test where we dip the paper (containing the sample) in a solution and the colour changes," the DG, CSIR said. “Speaking on the advantages of the testing kit, he said that the test′s ability to give accurate results in a short span of time is its biggest advantage.

"Through these kits, we hope to test people residing in villages as well which could not be possible with the RT-PCR test as a large number of instruments are required for the test," he said and added that the sensitivity and specificity are "as good as the RT-PCR test".

In a comment to Ani, Shekhar C Mande, Director General (CSIR) said, "This test kit only takes 30 minutes to test for COVID when the RT PCR takes around 4 to 5 hours. Also, this testing kit is three to five times cheaper than the RT PCR based test kit", Director General (CSIR) told ANI.

“We have extensively characterised a highly specific Cas9 that can recognise any DNA sequences. If we direct it to go and find out the sequence for COVID-19, then it can specifically identify that sequence and then form a complex with DNA," One of the senior scientists, who developed the test, Debojyoti Chakraborty said.

Courtesy: Gladstone Institutes

How does it work

The test is incredibly easy to use, which is crucial to its wider roll out. Speaking on the procedure of the test, he added: "On the strip, you get two lines: one line is a control line which is present in every strip that is being used and tells that the strip is working fine and then there is a test line which comes positive only if the COVID-19 sequence was present in the initial RNA."

He added further: "A negative sample will not have the test line appearing. So looking at the test line position you can visually see whether the patient test is positive or negative depending upon how the line forms on the strips."

Aptly timed for the market

The Feluda tests provide accurate results in a matter of minutes as opposed to the existing RT-PCR kits, which takes anywhere between 4 to 5 hours.

As the coronavirus pandemic continues wreak havoc across the world, governments and businesses are putting more and more emphasis on tracking and testing along with the drive to find the cure. A faster testing system will help businesses to identify symptomatic individuals who test positive for Covid-19 as well asymptomatic individuals, both of which pose a risk to workforce. This in turn will help business support employees returning to work as well as manage risk. Faster testing will also give staff more confidence that their employer is taking their safety and wellbeing seriously and reassure them about returning to their workplace. For affected sectors such as hospitality and travel, a faster detection test could be a gamechanger, ensuring customer, staff and passenger safety.