Rapid and sensitive detection of SARS-CoV-2 infection using quantitative peptide enrichment LC-MS analysis
- Science for Life Laboratory, Sweden
- Royal Institute of Technology, Sweden
- Waters Corporation, United Kingdom
- Waters Corporation, Sweden
- KTH Royal Institute of Technology, Sweden
- SISCAPA Assay Technologies, Inc, United States
- Karolinska Institutet, Sweden
Abstract
Reliable, robust, large-scale molecular testing for SARS-CoV-2 is essential for monitoring the ongoing Covid-19 pandemic. We have developed a scalable analytical approach to detect viral proteins based on peptide immunoaffinity enrichment combined with liquid chromatography - mass spectrometry (LC-MS). This is a multiplexed strategy, based on targeted proteomics analysis and read-out by LC-MS, capable of precisely quantifying and confirming the presence of SARS-CoV-2 in PBS swab media from combined throat/nasopharynx/saliva samples.<br />The results reveal that the levels of SARS-CoV-2 measured by LC-MS correlate well with their corresponding RT-PCR readout (r=0.79). The analytical workflow shows similar turnaround times as regular RT-PCR instrumentation with a quantitative readout of viral proteins corresponding to cycle thresholds (Ct) equivalents ranging from 21 to 34. Using RT-PCR as a reference, we demonstrate that the LC-MS-based method has 100% negative percent agreement (estimated specificity) and 95% positive percent agreement (estimated sensitivity) when analyzing clinical samples collected from asymptomatic individuals with a Ct within the limit of detection of the mass spectrometer (Ct ≤30). These results suggest that a scalable analytical method based on LC-MS has a place in future pandemic preparedness centers to complement current virus detection technologies.
Data availability
The ProteomeXchange ID for this dataset is PXD026366. The proteomics data have been deposited to Panorama Public (https://panoramaweb.org/sars-cov-2_siscapa.url; allowing for access to raw files and integrated peak areas from as well as visualization of all LC-MRM/MS chromatograms.
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Funding
No external funding was received for this work.
Ethics
Human subjects: The study was performed in accordance with the declaration of Helsinki and the study protocol ("Jämförande studier av Covid-19 smitta och antikroppssvar i olika grupper i samhället") was approved by the Ethical Review Board of Linköping, Sweden (Regionala etikprövningsnämnden, Linköping, DNR - 2020-06395). Informed consent and consent to publish, including consent to publish anonymized data, was obtained from all subjects.
Copyright
© 2021, Hober et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Rapid and sensitive detection of SARS-CoV-2 infection using quantitative peptide enrichment LC-MS analysis
eLife 10:e70843.
https://doi.org/10.7554/eLife.70843
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