Non-invasive skin swab samples enough to detect Covid infection: Study March 16, 2021 Currently, most popular approach to detect Covid is through RT-PCR test Researchers at the University of Surrey found after carrying out a study that non-invasive skin swab samples are enough to detect Covid-19 infection. Currently, the most popular approach to detect Covid-19 is through the RT-PCR test, which involves taking a swab of the back of the throat and far inside the nose. The study, published in the Lancet E Clinical Medicine, was carried out by chemists from Surrey who collaborated with Frimley NHS Trust and the Universities of Manchester and Leicester.