In order to curb the spread of Sars-CoV-2, it is necessary to test many people regularly and on site for the virus. Researchers at the Max Planck Institute for Evolutionary Anthropology and the St. Georg Hospital in Leipzig have developed an improved protocol for detecting Sars-CoV-2. This method can detect a positive sample in a pool of 25 uninfected samples in less than an hour.
Real-time quantitative PCR (qPCR) is the most commonly used diagnostic method to detect RNA viruses such as Sars-CoV-2, but it requires expensive laboratory equipment. Researchers are therefore looking for simpler but still reliable diagnostic alternatives. One such alternative is RT-LAMP (reverse transcription loop-mediated isothermal amplification). This test amplifies the desired virus target sequences at a constant temperature and requires minimal equipment compared to qPCR. In 2020 it was adapted for the detection of Sars-CoV-2. Instead of a swab, which many people find uncomfortable, this test can also be done on throat samples.
First author Lukas Bokelmann and colleagues have now developed an improved RT-LAMP color test called Cap-iLAMP (capture and improved loop-mediated isothermal amplification) that extracts, concentrates and amplifies viral RNA from a pool of gargle samples. After a short incubation, the test result - orange/red for negative, intense yellow for positive - can be interpreted visually or using a freely available smartphone app.
The improved test method outperforms similar methods in several respects. “Cap-iLAMP drastically reduces false positive results. In addition, this method can detect a single infected sample in a pool of 25 non-infected samples, reducing the technical cost per test to only about 1 euro per person,” says senior author Stephan Riesenberg, researcher at the Max Planck Institute for Evolutionary Sciences Anthropology. "Our method overcomes the problems associated with the standard RT-LAMP test and could also be applied to numerous other pathogens."
Source: Press release Max Planck Society from February 05.03.2021, XNUMX