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Updated: Jan 13, 2026
A Rapid, Multiplex Dual Reporter IgG and IgM SARS-CoV-2 Neutralization Assay for a Multiplexed Bead-Based Flow Analysis System
Published on: April 6, 2021
A Novel Flow Cytometry Array for High Throughput Detection of SARS-CoV-2 Antibodies
Benyue Zhang1, Zhuo Zhang2, Yichao Zhao1
1RayBiotech Life, Inc., Peachtree Corners, GA 30092, USA.
Background/Objectives:
Although the U.S. Food and Drug Administration (FDA) has approved one antiviral treatment and authorized others for emergency use, there is no fully effective antiviral therapy for coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Assays detecting virus-specific immunoglobulins (Ig) or nucleic acids in large-scale epidemiological, vaccine, and drug development studies remain limited due to high costs, reagent accessibility, and cumbersome protocols.
Methods:
A multiplex bead-based assay was developed to simultaneously detect human IgM, IgG, and IgA antibodies against the SARS-CoV-2 spike receptor binding domain (RBD) in serum using flow cytometry. Assay performance was evaluated for sensitivity, specificity, reproducibility, and cross-reactivity and compared to another immunoassay platform.
Results:
The assay enabled simultaneous measurement of three antibody isotypes across 624 samples within 2 h. Intra-plate coefficients of variation (CVs) ranged from 3.16 to 6.71%, and inter-plate CVs ranged from 3.33 to 5.49%, demonstrating high reproducibility. The platform also quantified background noise from nonspecific binding, facilitating straightforward data interpretation.
Conclusions:
This novel, flexible multiplex bead-based assay utilizing a well-established platform provides a rapid and reproducible approach for detecting SARS-CoV-2-specific antibodies. Its high throughput capacity and low variability make it well suited for large-scale epidemiological, vaccine, and therapeutic studies. The platform's adaptability further supports application to other infectious diseases, offering an ideal tool for broad immunological surveillance.
Insights
A new multiplex bead-based assay rapidly detects multiple SARS-CoV-2 antibodies (IgM, IgG, IgA) in serum. This high-throughput, reproducible method is ideal for large-scale COVID-19 research and vaccine development.
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.
