A team of scientists in India has developed an inexpensive paper-based test for testing coronaviruses that can produce immediate results like pregnancy tests.
This test has been named ‘Feluda’ after the famous fictional detective. This test is based on the gene editing technology named ‘Crisper’.
Scientists claim that the results of this test come within an hour and its price is only 500 rupees. This may become the world’s first paper-based technique for testing Kovid-19. The company will produce Feluda’s kit.
Testing done on 2000 samples
Vijay Raghavan, Professor Scientific Adviser to the Government of India Told the BBC, “It is easy, reliable and a large scale technology.”
Researchers at the Delhi-based Institute of Genomics and Integrative Biology (IGIB) have developed Feluda and tested it on samples from 2,000 patients in private laboratories. These include samples that have already been found corona positive.
He has got 96 percent sensitivity and 98 specificity in this test – these are the two scales that show the accuracy of a test.
If a test is very sensitive, then it will catch almost every positive case. Specificity is the measure of giving correct information about the absence of disease.
Approval for commercial use
The first test ensures that the wrong negative test is reduced, and the second one ensures that the wrong positive test is reduced.
Drug regulator of India has approved this test for commercial use. More than 65 lakh cases of corona infection have been reported in India and more than one lakh people have died.
How different from the pre-test
Over 1,200 labs across the country are testing nearly millions of samples every day to detect corona infection.
Generally the PCR test is reliable and it costs around Rs 2400. There is very little chance of getting wrong positive or negative results in it.
Blood samples are taken in an antigen test, it can also catch the symptoms of an earlier infection. It shows whether antibodies were made in your body to fight the disease.
However, these tests give more inaccurate results than PCR test because if there is a virus in the body but no antibodies have been produced by the time of the test then it will give negative results.
Global Health and Health Policies Researcher Dr. Anant Bhan According to, increasing the number of tests in India has not been easy. He told the BBC, “There are still no testing kits available or they have to wait a long time. We are doing too much antigen testing which is causing many negative negative results.”
They believe that the new feluda technique can replace the antigen test as it is cheaper and will give more accurate results.
There itself IGBI Director Arun Aggarwal Told the BBC, “The new test is a dependable test like the PCR test. Results come quickly and can be done easily in small labs.”
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The method of taking a sample for the Feluda test is similar to the PCR test – a swab is taken in the nose and the sample is taken. Tests are not being carried out in India with samples of spit.
In PCR test, the sample has to be sent to a lab where several tests are done on it. Feluda Crispar uses ‘Cluster Interspaced Short Pallidromic Repeats’ technique which is based on gene-editing.
According to the researchers, gene editing works like a processing in a word file. Just like you use the cursor on the computer to correct the wrong words in a file, remove the wrong letter and replace it with the correct letter. Similarly, gene editing can remove or insert a genome letter.
This technique is commonly used in the treatment of diseases associated with cells.
Crisper technology also works like cursors that go to the ‘signature letter’ of the corona virus and highlight them. Its results are given on a paper.
Just one blue line on the paper means that the result is negative, two blue lines indicate that the result is positive.
Stephen Testing of Harvard Medical School explains, “Testing is limited, we have to make every effort to improve it. So using Feluda is a good step.”
Research is being done in other countries also
Some companies in the US and UK are also doing research on such tests.
America’s Sherlock Bioscience has also created a paper-based technique which is very much discussed. The Food and Administration of America (FDA) has approved it for use in emergencies. It is based on DNA and RNA.
According to Dr. Thomas Sai of Harvard Global Health Institute, the ideal situation would be that this paper based technology can be used at home.
According to him “There are some problems with this technology. We cannot expect people from home to extract RNA and work on it.”
Feluda is different in this case.
Molecule Scientist Debojyoti Chakraborty in CSIR-IGBMR Told the BBC that they were working on a technology that would “help remove RNA at home and amplify it at home with PCR technology.”
“We are trying for a simple, inexpensive and accurate test technique,” says Debojyoti, who led the team that devised this technique.
At the same time, Stephen Kissler says, “India has an opportunity to prove the usefulness of this test because the population is so large and this is the right time. If it proves useful, then people all over the world will get the benefit.”
According to Kisler, the most important test is to be done now, we cannot rely on the vaccine.
He says, “The vaccine does not eliminate any disease at the root, but simply reduces its efficiency. So the role of testing will always be important.”