Hyderabad: CCMB dry swab test gets ICMR approval

Hyderabad: Centre for Cellular and Molecular Biology (CCMB), Hyderabad, has been testing samples for coronavirus since April 2020. Working closely with healthcare workers of Telangana, it identified some of the key issues that slow the testing process. The researchers developed a dry swab RNA-extraction free testing method for the COVID-19 virus.

In the conventional testing method, nasopharygeal or oropharyngeal swab samples are collected by sample collection centres.

These are transported to testing centres, sometimes even hundreds of kilometres away. The swab samples are generally placed in a liquid called Viral Transport Medium (VTM). To avoid leakage, the samples are packed heavily that adds on to sample processing times at both the sample collection and testing centres. Despite this, there are leakages from samples, which render those batches untestable and unsafe in handling.

The researchers at CCMB have found that VTM can be totally avoided and dry swab technique also does not require RNA extraction process, and can be directly used for RT-PCR testing with sensitivity and specificity similar to the current gold standard. This method has now received ICMR approval for use in settings where automated RNA extraction is not available.

Dr Rakesh Mishra, Director, CCMB, adds, "RNA extraction, even with automation, takes 4 hours for roughly 500 samples. VTM and RNA extraction both add a significant burden on money and time required for mass testing for coronavirus. We believe the technique's merit holds for all kinds of settings and has the potential of bringing the costs and time of testing by 40-50%. It is a game-changing technology as with the existing infrastructure, the throughput of COVID-19 screening can be enhanced several-fold with immediate effect while, at the same time, making the whole process safer."