Matrix-Assisted Laser Desorption and Ionization Time-of-Flight Mass Spectrometry Analysis for the Direct Detection of SARS-CoV-2 in Nasopharyngeal Swabs
Tomoya Yoshinari, Katsuhiko Hayashi, Shouhei Hirose, Kenji Ohya, Takahiro Ohnishi, Maiko Watanabe, Satoshi Taharaguchi, Hirohisa Mekata, Takahide Taniguchi, Takuya Maeda, Yuta Orihara, Rieko Kawamura, Sakura Arai, Yoshiro Saito, Yukihiro Goda, Yukiko Hara‐Kudo
Abstract
viral copies per swab and is approximately equivalent to the viral load of contagious patients. Seven NP-derived peptides were selected as the target molecules for the detection of SARS-CoV-2 in clinical specimens. The method detected between two and seven NP-derived peptides in 19 nasopharyngeal swab specimens from contagious COVID-19 patients. These peptides were not detected in four specimens in which SARS-CoV-2 RNA was not detected by PCR. Mutated NP-derived peptides were found in some specimens, and their patterns of amino acid replacement were estimated by accurate mass. Our results provide evidence that the developed MALDI-ToF MS-based method in a combination of straightforward purification steps and a rapid detection step directly detect SARS-CoV-2-specific peptides in nasopharyngeal swabs and can be a reliable high-throughput diagnostic method for COVID-19.