A team of scientists in India has developed a low-cost paper-based COVID-19 test that can quickly produce results similar to a pregnancy test. Krutika Pathi and Soutik Biswas of one of the famous Corporations analyzed how it works.
After a famous Indian fictional investigator and the experiment conducted which is based on a CRISPR gene-editing technology, Scientists estimate that this kit, named Feluda, will deliver results within an hour at a price of Rs 500.
Feluda will be developed and produced by India’s leading conglomerate Tata corporation and maybe the world’s first paper-based coronavirus test available in the market.
Chief Scientific Advisor of the Government of India, Professor K Vijay Raghavan, told reporters: It is a reliable, simple, accurate, scalable, and economical test.
Researchers from the Delhi-based CSIR-IGIB (Institute of Genomics and Integrative Biology), the private laboratory where Feluda was developed) and private laboratories tested samples from approximately 2,000 patients, including those that had previously been detected as positive coronavirus patients.
They found that the sensitivity of the new test was 96% and the specificity was 98%. The accuracy of the test is based on these two ratios. A highly sensitive test will detect almost all people with the disease; a high specificity test will correctly exclude almost all people without the disease.
The first one ensures that there will not be too many false-negative results. The second one does not have too many false positives. India’s drug regulatory agency has cleared the test for commercial usage.
India has more than 6 million confirmed infections, the second-highest number of COVID-19 cases in the world. So far, more than 1 lakh people in the country have died of this deadly disease.
Since its inception, India now tests 1 million samples every day in more than 1,200 laboratories across the country. It uses two tests.
The first is the time-tested gold-standard PCR or polymerase chain reaction swab test, which applies chemicals to amplify the genetic material of the virus in the laboratory. The second is the rapid antigen test, which works by identifying virus fragments in the sample.
PCR tests are usually reliable and cost up to Rs 2,500. It has a lower false-negative rate and a lower false-positive rate. As compared to this, antigen testing is cheaper. They are more accurate in detecting positive infections but produce more false negatives than polymerase chain reaction (PCR) tests.
Dr. Anant Bhan, a global health and health policy researcher, said that expanding the scope of testing in India does not mean easy access.
Dr. Bhan told the reporters: There is still a long waiting time and the kit is not available. We are doing a lot of rapid antigen testing, but there is a problem with false negatives.
He believes that the Feluda test may replace the PCR and antigen test because it may be relatively more accurate and cheap.
IGIB director Dr. Anurag Agarwal told: The new test has the reliability of PCR testing, is faster, and can be performed in small laboratories without advance and intricate machines.
The sample collection for the new test known as the “Feluda test” will be similar to the PCR test- a nasal swab is inserted a few inches into the nose to examine the presence of deadly coronavirus in the back of the nasal passage. India does not yet allow coronavirus testing from saliva samples.
In a regular PCR test, the sample is sent to an authorized laboratory, where it must go through several cycles before to recover enough virus.
The new Feluda test uses clusters regularly interspaced short palindromic repeats (CRISPR) or a gene-editing technique to detect viruses.
According to the researchers, gene editing works similarly to word processing-like using a cursor to correct typos by deleting the wrong letters and inserting the correct ones. The technique is very precise and can delete and add unique genome letters. Gene editing is mainly used to prevent infection and treat diseases such as sickle cell illness.
When a Feluda is used as a diagnostic tool, the Crispr technology latches on to a set of letters with a new coronavirus signature gene, highlighting it, and making it legible on a piece of paper.
Two blue lines indicate a positive result, and one blue line indicates that the test has returned negative.
Dr. Stephen Kissler, a researcher at Harvard Medical School, said: Testing is still an insufficient resource, and we need to do everything we can to improve its accessibility. So Feluda is a significant step in this direction.
Dr. Thomas Tsai of the Harvard Institute of Global Health said that the Crispr-based experiment is part of the third wave of tests after the PCR and antigen testings, which are extremely time-consuming and laborious.
In the United Kingdom and the United States, research laboratories and several companies are developing similar paper strip experiments, which can be inexpensive and mass-produced. One of the most concerning issues is the paper test strip developed by Sherlock Bioscience, which has been approved by the U.S. FDA (Food and Drug Administration) for emergency use.
The test claims to detect the unique ancestral fingerprint of any RNA or DNA sequence in almost any organism or pathogen. RNA or DNA are sister molecules, responsible for collecting all the genetic information that supports life.
Dr. Tsai said: The ideal and final test will be a paper test that can be performed at home. But, of course, this technology has some biological limitations-we can’t expect individuals to extract and amplify RNA at home. This is how the Feluda test may eventually change our view of genetic editing-based diagnostic tests.
A molecular scientist at CSIR-IGBMR, Dr. Debojyoti Chakraborty, who is a key member of the team that developed Feluda, told the reporters that they are working on a test prototype, You can use a PCR machine to extract and amplify RNA at home.
Dr. Chakraborty said: We are trying to have an affordable, simple, and truly immediate care test, so extensive testing is not limited by machines and humans.
Dr. Kissler said: India has the opportunity to demonstrate the value of this test because it has a large population and can be carried out when needed. If their efficacy is proven, it may bring benefits that ripple worldwide.
Vaccines are essential for a full recovery from the pandemic, but according to Dr. Kissler, reliable and easily accessible tests are also the significant keys to achieving a “sense of normalcy.” This Feluda- paper-based COVID-19 test could be a game-changer. He said: In the ideal world I envision, taking a test is as easy as brushing your teeth or baking bread.