IISc develops new Covid-19 antibody test

Researchers at the Indian Institute of Science (IISc) have made a breakthrough development of a semi-quantitative electrochemical ELISA test for Covid-19. The test can determine levels of Covid-induced IgM and IgG antibodies.

The Central Drugs Standard Control Organisation (CDSCO) has issued a licence to manufacture the test for sale, and the scientists behind the project say they plan to deploy the product in the market in the next couple of weeks.

Invented by PathShodh Healthcare, a start-up incubated at the Society for Innovation and Development (SID) at the IISc, the test can measure the electrochemical redox activity of IgM and IgG antibodies specific to the Sars-CoV-2 Spike Glycoprotein (S1).

The S1 protein has a Receptor Binding Domain (RBD) which latches on to the host cell’s ACE2 receptors before infection. Hence, those antibody tests which target the S1 spike protein are more representative of an immune response against infection compared to those that target the Nucleocapsid (N) protein.

Vinay Kumar, CEO and co-founder of PathShodh, said: “This novel technology can detect Covid-19 antibodies all the way down to the nanomolar concentration. It can work with venous or capillary (finger-prick) whole blood samples as well as serum samples.”

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The IISc added that PathShodh’s technique, which is protected through US and Indian patent applications, is a major departure from the qualitative rapid antibody tests in the market, which are primarily based on the lateral flow ELISA technique.

“The capability to quantify the Covid-19 antibody concentration will be crucial in estimating the declining antibody response over time and hence its possible impact on immunity against recurrence of infection. The technique will also play a big role in elucidating seroconversion response to Covid-19 vaccines, and thereby play a supporting role in vaccination programmes in the future,” explained Professor Navakanta Bhat, Dean, Centre for Nano Science and Engineering (CeNSE), IISc, who is also the co-founder of PathShodh Healthcare.

The test uses a Lab-on-Palm platform called ‘anuPathTM’ which has also been developed by PathShod. This platform interfaces with disposable test strips and immunoreceptors specific to Covid-19 antibodies. The results are automatically displayed by the handheld reader.

The technology also includes on-board memory to store more than one lakh real-time test results, touch screen display, rechargeable battery, Bluetooth connectivity to smartphone and cloud storage, capabilities to map the patient data to Aadhaar numbers and the possibility of connecting test data through APIs to Aarogya Setu.

“PathShodh’s current production capacity is about one lakh tests per month, and we can scale this up further by augmenting the manufacturing infrastructure,” Kumar said.

The scientists said that they were simultaneously working on integrating Rapid Antigen Tests on the same platform.