Why in news?
- An accurate and low-cost strip test called “Feluda” that can detect the coronavirus disease within one hour is expected to be available for the first phase of testing by July 2020.
- Called Feluda, the test is named after a fictional detective created by the late Satyajit Ray – and it is also an acronym for FNCAS9 Editor-Linked Uniform Detection Assay.
How does Feluda Work?
- The test uses CRISPR gene-editing technology to identify and target the genetic material of Sars-CoV2, the virus that causes Covid-19.
- The CRISPR-based Feluda testing works by combining CRISPR biology and paper strip chemistry. Briefly, Cas9 protein, a component of the CRISPR system, is barcoded to interact specifically with the Sars-CoV2 sequence in the patient’s genetic material.
- The complex of Cas9 with Sars-CoV2 is then applied to a paper strip, where using two lines (one control, one test) make it possible to determine if the test sample was infected with Covid-19.
- The entire diagnostic process takes about one hour, starting from RNA to giving a visual readout on the strip.
- Unlike other CRISPR tests that use CAS12 and CAS13 proteins to detect Sars-CoV2, the CSIR-IGIB kit technology uses CAS9 protein (CRISPR-associated protein 9) to identify and bind to the target sequence.
Significance of Feluda
- Most labs are working with PCR (polymerase chain reaction)-based technology, which is costly and needs a lab set-up.
- Feluda paper strip does not require (biosafety) Level-2 or Level-3 lab for testing and can be done in any path lab.
- Feluda is not limited to Covid-19.
- Each Feluda test costs Rs 500 in the lab, bringing down the current cost of Rs. 4,500 for RT-PCR.
What is CRISPR?
CRISPR, which is short for Clustered Regularly Interspaced Short Palindromic Repeats, is a gene-editing technology that can be used to detect a specific snippet of DNA from a sequence. It can also be used turn genes on or off without altering their sequence.
|UPSC 2019 Prelims Question: |
What is Cas9 protein that is often mentioned in news?
(a) Molecular scissors used in targeted gene editing
(b) A biosensor used in the accurate detection of pathogens in patients
(c) A gene that makes plants pest-resistant
(d) Herbicidal substance synthesized in genetically modified crops
-Source: Hindustan Times