CSIR-NEERI’s Saline Gargle Sampling Method May Eliminate The Need Of Swabs To Detect Covid-19

A new testing process could completely remove the need for nasal and throat swab tests to detect Covid-19 in India.

While many people feel uncomfortable when they think about swab testing, a Maharashtra-based institute has come up with a novel approach—gargling—to detect Covid-19.

The National Environmental Engineering Research Institute (NEERI), which is part of the Council of Scientific and Industrial Research (CSIR) has received a nod from the Indian Council for Medical Research (ICMR) for its “saline gargle” RT-PCR test.

It was the CSIR-NEERI’s Environmental Virology Section which has developed the new testing method.

How It Works

This innovative test is completely non-invasive and no special training is required to conduct the testing procedure.

As per the developers, self-sampling is also possible.

Compared to RT-PCR, this new technique—developed by senior scientist Dr Krishna Khairnar and his team—can give results at a faster rate, with no need for RNA extraction.

“There is a saline water solution in a container….you have to take the solution in your mouth, gargle it for 15 seconds and then rinse your mouth in another 15 seconds and put it in the same container,” said Dr Khairnar.

A tube filled with sterile saline will be given to an individual, who will take the solution and gargle for 15 seconds.

Then the person has to rinse the liquid, put it in the tube and then the sample will be taken to the lab and incubated.

“Simple room temperature incubation in a buffer, followed by heating for a few minutes is good enough to give a reasonably good RNA template for Direct RT-PCR,” explained Dr Khairnar.

He also noted that there is no need for nasopharyngeal swab, oropharyngeal swab and viral transport medium—which means a huge reduction of swab usage.

Dr Khairnar added that medical-waste generation during the sample collection will be less.

It is a very “patient-friendly technique” which minimizes long queues at Covid-19 testing facilities.

Dr Khairnar also noted that since there is a possibility that the third wave would affect children, taking their samples through the gargling method will be much easier than others.

In November 2020, a similar test kit developed by the American company OralDNA Labs received an emergency use authorisation from the Food and Drug Administration (FDA) in the United States.

The product became the first device with a EUA for a saline 30-second swish and gargle collection.