A direct RT-qPCR approach to test large numbers of individuals for SARS-CoV-2

December 31, 2020

NOMIS Awardee Svante Pääbo and colleagues developed a very efficient PCR test that pools gargle lavage samples. The test was implemented in a retirement home and was used to test approximately 300 employees at the the Max Planck Institute three times per week until June 2020, enabling the institute to remain open throughout the pandemic. In addition, the test was implemented at other institutions and was also part of a pilot project to allow larger gatherings without masks or distancing requirements at the first rave party in Germany since the start of the pandemic. The PCR test was presented in PLoS One.


The COVID-19 pandemic has led to substantial morbidity and mortality in elderly and immunocompromised individuals, particularly in long-term care facilities. Up to half of the fatalities in Europe have been observed in retirement homes, where advanced age and chronic underlying health conditions seem to predispose residents. Therefore, it is necessary to prevent that infected personnel and visitors enter institutions where vulnerable individuals live.

However, infected individuals are often asymptomatic, resulting in a considerable rate of presymptomatic transmission of SARS-CoV-2. Furthermore, the viral load, and presumably the ability to transmit the infection, is highest at the time of symptom onset or just before. To prevent the spread of infection to institutions, one would therefore ideally test all individuals entering the facilities every time they do so. However, most commercially available viral test systems are too expensive and too laborious for such a strategy. In addition, swab kits and RNA extraction kits may run out during a pandemic.

Here, we present a safe, cheap and fast PCR-based approach to detect individuals with high levels of SARS-CoV-2 without the need for nasopharyngeal swabs or RNA extraction. We performed daily tests of all staff and residents of a local nursing home previously affected by COVID-19. We suggest that this approach could be used to test staff members and visitors of retirement homes and other institutions.

Continue reading this PLoS One publication