New Delhi: The National Environmental Engineering Research Institute (NEERI) has developed a simple and fast method of swab collection and processing for RT-PCR coronavirus test which could be used in rural and tribal areas.
The method is simple, fast, cost-effective, patient-friendly and comfortable, the Council for Scientific and Industrial Research (CSIR) said.
It is well-suited for rural and tribal areas, given minimal infrastructure requirements, it said. The Nagpur-based NEERI is a constituent laboratory of the CSIR.
Krishna Khairnar, Senior Scientist, Environmental Virology Cell at NEERI, said the swab collection method requires time. Moreover, since it is an invasive technique, it is a bit uncomfortable for patients.
“Sometimes, it is also lost in the transport of the sample to the collection centre. On the other hand, the Saline Gargle RT-PCR method is instant, comfortable and patient-friendly. Sampling is done instantly and results will be generated within three hours,” he said.
The method is non-invasive and so simple that a patient can collect the sample himself, said Khairnar.
Collection methods like nasopharyngeal and oropharyngeal swab collection require technical expertise and they are also time-consuming. In contrast, the Saline Gargle RT-PCR method uses a simple collection tube filled with saline solution, he said.
The patient gargles the solution and rinses it inside the tube. This sample in the collection tube is taken to the laboratory where it is kept at room temperature, in a special buffer solution prepared by NEERI.
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An RNA template is produced when this solution is heated, which is further processed for Reverse Transcription-Polymerase Chain Reaction (RT-PCR).
This particular method of collecting and processing the sample enables to save on the otherwise costly infrastructural requirement of RNA extraction. The method is environment-friendly as well since waste generation is minimised, Khairnar said.
The Nagpur Municipal Corporation has given permission to go ahead with the method, following which testing has begun at NEERI, the CSIR said.
Scientists at the CSIR’s Institute of Genomics and Integrative Biology in Delhi developed a low-cost coronavirus test method last year that does not require any expensive RT-PCR machines for the detection of the pathogen.
Named after ‘Feluda’, the detective character in legendary filmmaker Satyajit Ray’s stories, the test starts the same way as a normal real-time reverse transcription-polymerase chain reaction (RT-PCR), which is the extraction of ribonucleic acid (RNA) and its conversion to deoxyribonucleic acid (DNA).
It then differs by using a specifically designed PCR reaction to amplify a part of the viral nucleic acid sequence. Then a highly specific CRISPR, FnCAS9, developed at IGIB, binds to that sequence.
Using the innovative chemistry on a paper strip, the CRISPR complex bound to that specific sequence can be visualised as a positive band – like one sees in simple pregnancy tests. The total time required for the test is less than one hour.
Last week, the Department of Science and Technology’s Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST) in Thiruvanathapuram announced that it had developed an RT-PCR kit that has a higher accuracy of detecting COVID-19 across various mutant strains of the coronavirus.