Establishing an internal quality control method for the stable extraction of nucleic acids of severe acute respiratory syndrome coronavirus 2 and RT‐PCR‐based detection

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the causative agent of the coronavirus disease 2019 (COVID‐19), is detected using real‐time RT‐PCR. However, there are limitations pertaining to quality control, particularly with respect to establishing quality control measures for extraction of viral nucleic acids. Here, we investigated the quality control measures for the various processes using an extrinsic quality control substance and quality control charts. METHODS: An extrinsic quality control substance was added to the sample, and then, real‐time RT‐PCR was performed. Samples with negative test results and the corresponding data were analyzed; a quality control chart was created and examined. RESULTS: Data analysis and the quality control charts indicated that SARS‐CoV‐2 could be reliably detected using real‐time RT‐PCR, even when different nucleic acid extraction methods were used or when different technicians were employed. CONCLUSION: With the use of quality control substances, it is possible to achieve quality control throughout the process—from nucleic acid extraction to nucleic acid detection—even upon using varying extraction methods. Further, generating quality control charts would guarantee the stable detection of SARS‐CoV‐2.