Performance of the GeneSoC Rapid PCR System in Detection of SARS-CoV-2 from Saliva Specimens

Since the beginning of the coronavirus disease 2019 (COVID-19) outbreak, the detection of SARS-CoV-2 by nucleic acid amplification tests, including reverse transcription (RT)-PCR, has been the gold standard for diagnosis (1, 2). Rapid and accurate detection of SARS-CoV-2 is of great importance, nevertheless, RT-PCR requires several hours of turnaround time (TAT), attributable to the nucleic acid extraction (sample preparation) and amplification processes. GeneSoC (Kyorin Pharmaceutical Co., Ltd., Tokyo, Japan) is a rapid PCR system that detects SARS-CoV-2 RNA (N2 region) sequences in less than 15 min using microfluidic thermal cycling technology requiring simple procedures (3). The performance of SARS-CoV-2 RNA detection has been reported for nasopharyngeal swab specimens (4, 5). In the COVID-19 era, saliva is another commonly used specimen for diagnosing COVID-19 with comparable sensitivity and specificity to nasopharyngeal swabs (6–8). However, collection, storage, and processing methods for saliva specimens are not standardized sufficiently (9), so the study comparing saliva and other types of specimens needs careful interpretation before clinical application. In addition, sample preparation, including nucleic acid extraction and purification, is another time-consuming process for using saliva as test specimen. Therefore, individual evaluation for SARS-CoV-2 detection method in saliva is necessary. GeneSoC Lysis Buffer (GLB) is a saliva sample preparation kit that enables saliva sample preparation (nucleic acid extraction) in several minutes. The objective of this study is clarifying the performance of GLB and the GeneSoC N2 detection kit (N2 kit) using clinical saliva samples (Institutional Review Board approval number, 21051706-2).