Cov2MS: an automated matrix-independent assay for mass spectrometric detection and measurement of SARS-CoV-2 nucleocapsid protein in infectious patients

• DOI: 10.1101/2022.02.09.22270547
• Publication Date: 2022-02-11T03:15:16Z
• Authors: Bart Van Puyvelde; Katleen Van Uytfa...; Laurence Van Oude...; Ralf Gabriels; Tessa Van Royen; Arne Matthys; Morteza Razavi; Richard Yip; Terry Pearson; Marijn van Hulle; Jan Claereboudt; Kevin Wyndham; Don Jones; Xavier Saelens; Geert A. Martens; Christophe Stove; Dieter Deforce; Lennart Martens; Johannes P.C. Vis...; N. Leigh Anderson; Maarten Dhaenens
• Keywords: Sample Preparation

Abstract INTRODUCTION The pandemic readiness toolbox needs to be extended, providing diagnostic tools that target different biomolecules, using orthogonal experimental setups and fit-for-purpose specification of detection. Here we build on a previous Cov-MS effort used liquid chromatography-mass spectrometry (LC-MS) describe method allows accurate, high throughput measurement SARS-CoV-2 nucleocapsid (N) protein. MATERIALS METHODS We Stable Isotope Standards Capture by Anti-Peptide Antibodies (SISCAPA) technology enrich quantify proteotypic peptides the N protein from trypsin-digested samples COVID-19 patients. RESULTS Cov 2 MS assay was shown compatible with variety sample matrices including nasopharyngeal swabs, saliva blood plasma increased sensitivity into attomole range, up 1000-fold increase compared direct detection in matrix. In addition, strong positive correlation observed between SISCAPA antigen qPCR beyond quantification cycle (Cq) 30-31, level where no live virus can cultured automatable “addition only” preparation, digestion protocol, peptide enrichment subsequent reduced dependency upon LC allow analysis 500 per day instrument. Importantly, allowed pooled containing single PCR mixed 31 negative samples, without loss sensitivity. easily multiplexed also propose for Influenza A B CONCLUSIONS described is agnostic respect matrix or pooling strategy increasing multiplexed. Additionally, eliminates interferences due protein-protein interactions those caused anti-virus antibodies. adapted test many pathogens could provide tool enabling longitudinal epidemiological monitoring large numbers within population, applied as an early warning system.