TY - JOUR T1 - Pitfalls in SARS-CoV-2 PCR diagnostics JF - bioRxiv DO - 10.1101/2020.06.03.132357 SP - 2020.06.03.132357 AU - Kerstin Wernike AU - Markus Keller AU - Franz J. Conraths AU - Thomas C. Mettenleiter AU - Martin H. Groschup AU - Martin Beer Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/06/04/2020.06.03.132357.abstract N2 - To combat the COVID-19 pandemic, millions of PCR tests are performed worldwide. Any deviation of the diagnostic sensitivity and specificity will reduce the predictive values of the test. Here, we report the occurrence of contaminations of commercial primers/probe sets with the SARS-CoV-2 target sequence of the RT-qPCR as an example for pitfalls during PCR diagnostics affecting diagnostic specificity. In several purchased in-house primers/probe sets, quantification cycle values as low as 17 were measured for negative control samples. However, there were also primers/probe sets that displayed very low-level contaminations, which were detected only during thorough internal validation. Hence, it appears imperative to pre-test each batch of reagents extensively before use in routine diagnosis, to avoid false-positive results and low positive predictive value in low-prevalence situations. As such, contaminations may have happened more widely, COVID-19 diagnostic results should be re-assessed retrospectively to validate the epidemiological basis for control measures.Competing Interest StatementThe authors have declared no competing interest. ER -