The indigenously developed Feluda (FNCAS9 Editor-Limited Uniform Detection Assay) paper strip test for Covid-19 will be launched in Delhi on Thursday and be available in other states by November end, according to reports. The test is called a cheaper, faster and simpler alternative to RT-PCR, the gold standard in the diagnosis of Covid, and more accurate than an antigen test.
Feluda will be launched in Delhi by the Tata group in collaboration with the Apollo group of hospitals, according to Hindustan Times. The report also said that Tata Medical and Diagnostics Ltd (TataMD) had announced earlier this month that the paper-strip kit would be marketed as “TataMD’s CHECK”.
The test gets its name from the fictitious detective in a series of novels written by Satyajit Ray.
Here are five things you need to know about the new test:
1. Union Health Minister Harsh Vardhan had said last month that based on tests in over 2,000 patients during the trials at the Institute of Genomics and Integrative Biology (IGIB) and testing in private labs, the test showed 96% sensitivity and 98% specificity.
“This compares favourably to ICMR’s current acceptation criteria of RT-PCR Kit of at least 95% sensitivity and at least 99% specificity,” he stated.
2. The Feluda paper strip test has been developed by Council of Scientific and Industrial Research and Institute of Genomics and Integrative Biology (CSIR-IGIB) and has been approved by the Drug Controller General of India for a commercial launch.
“The kit has already been validated by the Department of Atomic Energy’s National Centre for Biological Sciences, Bangalore,” Vardhan had said.
3. An ICMR advisory noted that the paper-strip uses CRISPR gene-editing technology to identify and target the genetic material of SARS-CoV-2, the virus that causes Covid-19 in less than an hour.
The advisory also said that as claimed by the manufacturer, no further RT-PCR based confirmation is required for samples that are confirmed as positive or negative by the CRISPR SARS-CoV-2 test, according to PTI.
4. In the advisory, the ICMR also explained how the test works. “The test works by identifying SARS-CoV-2 virus strain and uses a Thermal Cycler instead of a qPCR machine for conducting the test.” The Wire detailed the process of taking a sample for the Feluda test. The sample collection for the Feluda test will be similar to RT-PCR – a swab that collects the sample from the nasopharyngeal area, it said (read more here).
Dr Debojyoti Chakraborty, senior scientist at CSIR-IGIB, was quoted as saying by The Indian Express that Cas9 protein is barcoded to interact with the SARS-CoV2 sequence in the patient’s genetic material. “The Cas9-SARS-CoV2 complex is then put on the paper strip, where using two lines (one control, one test) makes it possible to determine if the test sample was infected with Covid-19.”
5. Existing government or private laboratories already approved by the ICMR for RT-PCR based testing may use this new CRISPR test if the laboratory desires to do so, ICMR said in the advisory.
No further approval is required from ICMR for existing laboratories.
(With PTI inputs)