NEW DELHI: IIT Delhi 's Kusuma School of Biological Sciences (KSBS) has developed a method to detect Covid-19 which will significantly reduce the cost of testing, making it affordable for a large population in the country.The detection assay has been validated at Indian Council of Medical Research (ICMR) with a sensitivity and specificity of 100% making IIT Delhi the first academic institute to have obtained the ICMR approval for a real-time PCR-based diagnostic assay.The development comes against the backdrop of ICMR halting the testing for Covid-19 cases through China-made test kits because of massive variation in test results, compounding the challenge to check and contain the pandemic.The current testing methods available are "probe-based" while the one developed by the IIT team is a "probe-free" method, which reduces the testing cost without compromising on accuracy, officials said.Using comparative sequence analyses, the IIT Delhi team identified unique regions (short stretches of RNA sequences) in the COVID-19 /SARS COV-2 genome. These regions are not present in other human corona viruses providing an opportunity to specifically detect Covid-19.This method uses primers targeting unique regions of Covid-19 that were designed and tested using real time PCR. These primers specifically bind to regions conserved in over 400 fully sequenced Covid-19 genomes. This highly sensitive assay was developed by extensive optimization using synthetic DNA constructs followed by in vitro generated RNA fragments.This is the first probe-free assay for Covid-19 approved by ICMR and it will be useful for specific and affordable high throughput testing. This assay can be easily scaled up as it does not require fluorescent probes. The team is targeting large scale deployment of the kit at affordable prices with suitable industrial partners as soon as possible.Primer sets, targeting unique regions in the spike protein of Covid-19, were designed and tested using real time polymerase chain reaction. The primers designed by the group specifically bind to regions conserved in over 200 fully sequenced Covid-19 genomes. The sensitivity of this in-house assay is comparable to that of commercially available kits.The team at IIT claims that their test can be performed at a much cheaper cost and hence will be affordable for general public.The research team includes PhD scholars Prashant Pradhan, Ashutosh Pandey and Praveen Tripathi, post-doctoral fellows Drs Parul Gupta and Akhilesh Mishra and professors Vivekanandan Perumal, Manoj B Menon, James Gomes and Bishwajit Kundu.(With inputs from PTI)