Microscopy-based assay for semi-quantitative detection of SARS-CoV2 specific antibodies in human sera
Authors: Pape and Remme et al.
Link to paper: https://www.biorxiv.org/content/10.1101/2020.06.15.152587v1
Tags: Microscopy, image analysis
Development of a semi-automated imaging pipeline for SARS-CoV2 antibody detection that can be tuned for desired specificity/sensitivity
Development of a Fiji based open-source software- The PlateViewer for interactive visualization of high-throughput microscopy data- images, segmentation and resulting plots.
The researchers developed a semi-quantitative immunofluorescence-based assay for detection of Sars-CoV-2 specific antibodies in human serum with higher specificity and sensitivity than ELISA. SARS-CoV2 infected VeroE6 are incubated with patient or negative control sera (for background correction) and anti-dsRNA antibody followed by labelled anti-human IgG, A and M. Acquired images are pre-processed to remove barrel artefacts and cells are segmented via seeded watershed; dsRNA staining is used to classify each cell as infected or not infected. The scoring of background corrected serum channels (IgG, A and M) is computed as ratio of median fluorescence intensity of respective channel in infected and non-infected cells. Two quality controls identify and discards outliers. All source code is available under the permissive MIT license at https://github.com/hci-unihd/batchlib.
Impact for SARS-CoV2/COVID19 research efforts
Develop diagnostic tools for SARS-CoV2/COVID19
In silico study / bioinformatics study
In vitro study
Strengths and limitations of the paper
Novelty: The first study to develop a full high-throughput semi-automated imaging workflow detecting anti-SARS-CoV2 antibodies of any class with a higher specificity than ELISA
Standing in the field:Supports the literature regarding the abundance of specific anti-SARS-Cov2 antibodies being greater at d14 post symptom onset. Uses well established image segmentation algorithms.
Appropriate statistics: Yes, the analysis algorithms are documented and well established in the field. Also, all source code is available open source under the permissive MIT license at https://github.com/hci-unihd/batchlib.
Viral model used:VeroE6 cell infected with SARS-CoV2
Translatability:Yes, the assay can be used for population based screening for SARS-CoV2 specific Ab presence in the serum as it offers higher specificity than ELISA
Main limitations: comparing to ELISA: the assay requires wide-filed microscope compatible for high-throughput imaging-e.g. automated stage that can fit 96 well plate and a suitable computer for image analysis. The whole assay is 3 days long and it requires BSTL3 and maintenance of SARS-CoV2 stocks.