A Novel Flow Cytometry Array for High Throughput Detection of SARS-CoV-2 Antibodies

Area of Science:

• Immunology
• Virology
• Assay Development

Background:

• Current diagnostic and research tools for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited by cost, reagent availability, and complex protocols.
• Effective antiviral therapies for coronavirus disease 2019 (COVID-19) are still under development, necessitating robust methods for immunological studies.

Purpose of the Study:

• To develop and validate a novel multiplex bead-based assay for simultaneous detection of SARS-CoV-2 specific IgM, IgG, and IgA antibodies.
• To assess the assay's performance characteristics, including sensitivity, specificity, reproducibility, and cross-reactivity.

Main Methods:

• A multiplex bead-based assay using flow cytometry was developed to detect human antibodies against the SARS-CoV-2 spike receptor binding domain (RBD).
• The assay was validated by evaluating its sensitivity, specificity, reproducibility, and cross-reactivity, with comparisons to an existing immunoassay platform.

Main Results:

• The assay successfully measured three antibody isotypes (IgM, IgG, IgA) simultaneously in 624 serum samples within 2 hours.
• High reproducibility was demonstrated with intra-plate coefficients of variation (CVs) between 3.16-6.71% and inter-plate CVs between 3.33-5.49%.
• The platform effectively quantified background noise, enabling clear data interpretation.

Conclusions:

• A novel, flexible multiplex bead-based assay offers a rapid and reproducible method for detecting SARS-CoV-2 specific antibodies.
• The assay's high throughput and low variability make it suitable for large-scale epidemiological studies, vaccine development, and therapeutic research.
• The adaptable platform can be applied to other infectious diseases, supporting broad immunological surveillance.