Validation of SARS-CoV-2 Detection Assay

A total of 22 respiratory pathogens were used in our initial validation analysis of the specificity of the study primers. The strain names of these 22 pathogens are listed in Table 1. The Middle East respiratory syndrome coronavirus (MERS-CoV) EMC strain was kindly provided by Dr. Ron A. M. Fouchier, Erasmus Medical Center, Rotterdam, the Netherlands. The SARS-CoV Frankfurt 1 strain was kindly provided by J. Ziebuhr, University of Würzburg, Germany. The clinical isolates of human coronaviruses (HCoV)-HKU1, -OC43, -NL63, and -229E were described by previous studies.^{31 (link)–33 (link)}In vitro-transcribed RNA (GenBank accession number MN908947), synthesized using a ScriptMax Thermo T7 Transcription Kit (TOYOBO, Osaka, Japan), was used to determine the detection limit of the Loopamp SARS-CoV-2 Detection kit (Eiken Chemical, Tokyo, Japan).