According to the World Health Organisation (WHO), testing is the key to combat the novel coronavirus. However, with a massive, dense population in a country like India, testing in large numbers is impractical and not entirely affordable.
Keeping this in mind, a low-cost COVID-19 test kit developed by the Indian Institute of Technology (IIT), Delhi has been launched. According to researchers, the current testing methods available are “probe-based”, while the one developed by the IIT is a “probe-free” method, which reduces the testing cost, but ensures accuracy.
Normal RT-PCR technology uses a custom-synthesised probe that looks for a specific region of the particular viral RNA, in this case, the novel coronavirus. The primer and the probe bind to specific locations along the specific viral genome. When the PCR reactions take place, the fluorescent signal indicates the presence or absence of the virus.
“Whenever there is an amplification of genetic material in a small tube, that is the PCR part. It is detected by a fluorescent signal that usually comes from a fluorescent probe in almost all RT-PCR assays. For this product, we are using a fluorescent dye as the signal — it is an old technology that we have been using,” said Professor Vivekanandan Perumal, lead researcher, IIT Delhi while speaking to India Science Wire.
They compared the genome sequence of SARS-CoV-2 and other human coronaviruses. The researchers identified specific regions of the novel coronavirus genome that serve an identification function similar to that of a human fingerprint. These short stretches of the genome are a unique signature of the virus.
“These unique regions are not present in other human coronaviruses, providing an opportunity to specifically detect COVID-19,” said Professor Perumal.
The spike protein of SARS-CoV-2 is unique and hence, the researchers chose primers that could target the genome stretches on the spike proteins. “Primer sets, targeting unique regions in the spike protein of COVID-19, were designed and tested using real-time polymerase chain reaction,” Professor Perumal explained.
Over a lapse of six months, several mutations have taken place and a number of variants of the virus have emerged.
This raised the question of whether each strain of the virus will or will not differ from the other. To ensure that their primer is able to capture the most conserved regions of the genome sequence, researchers tested it with about 200 fully-sequenced novel coronavirus genomes.
Since their assay uses only the primer without the requirement for a probe, the cost of the test went down notably. Scientists also ensured that their assay was robust and had the sensitivity of a probe-based RT-PCR. “The sensitivity of this in-house assay is similar to that of commercially available kits,” said Professor Perumal. The research team started working on the kit during the end of January.
The institute gave a non-exclusive open license to companies for commercialising the test, but with a price rider. “This should change the paradigm of COVID-19 testing in the country, both in terms of scale and cost. The product, approved by the ICMR (Indian Council of Medical Research) and DCGI (Drug Controller General of India), is being launched now,” said Dr V Ramgopal Rao, Director, IIT Delhi.
“The company Newtech Medical Devices, using IIT Delhi technology, can conduct two million tests per month at an extremely affordable cost. This is a true example of lab-to-market,” said Rao.
While the institute had assigned a price of ₹500 per kit, Newtech Medical Devices, which is launching the kit under the name ‘Corosure’, has not announced the price yet.
Union Human Resource Development (HRD) Minister Ramesh Pokhriyal and Minister of State for HRD Sanjay Dhotre launched the kit.
(With inputs from India Science Wire)