Towards Quantitative and Standardized Serological and Neutralization Assays for COVID-19

Published

March 8, 2021

Author(s)

Linhua Tian, Elzafir B. Elsheikh, Paul Patrone, Anthony Kearsley, adolfas Gaigalas, Sarah L. Inwood, Sheng Lin-Gibson, Dominic Esposito, Lili Wang

Abstract

Quantitative and robust serology assays are critical measurements underpinning global COVID-19 response to diagnostic, surveillance, and vaccine development. Here, we report a proof-of-concept approach for the development of quantitative, multiplexed flow cytometry-based serological and neutralization assays. The serology assays test the IgG and IgM against both the full-length spike antigens and the receptor binding domain (RBD) of the spike antigen. Benchmarking against an RBD-specific SARS-CoV IgG reference standard, the anti-SARS-CoV-2 RBD antibody titer was quantified in the range of 37.6 µg/mL to 31.0 ng/mL. The quantitative assays are highly specific with no correlative cross-reactivity with the spike proteins of MERS, SARS1, OC43 and HKU1 viruses. We further demonstrated good correlation between anti-RBD antibody titers and neutralizing antibody titers. The suite of serology and neutralization assays help to improve measurement confidence and are complementary and foundational for clinical and epidemiologic studies.

Citation

International Journal of Molecular Sciences

Pub Type

Journals

Citation

Tian, L. , Elsheikh, E. , Patrone, P. , Kearsley, A. , Gaigalas, A. , Inwood, S. , Lin-Gibson, S. , Esposito, D. and Wang, L. (2021), Towards Quantitative and Standardized Serological and Neutralization Assays for COVID-19, International Journal of Molecular Sciences (Accessed September 17, 2025)