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SARS-CoV-2 neutralizing antibody in vitro bioassay service

The Coronavirus disease (COVID-19) pandemic has become the greatest international concern of public health in 2020. The neutralizing antibody designed to block the binding of SARS-CoV-2 Spike protein with its receptor, ACE2, is one of the most promising ways of treatment to help individual immune system stop the viral infection. ProBio has developed a platform for SARS-CoV-2 neutralizing antibody in vitro bioassay, providing GMP-compliant analytical services to support the process development, GMP production, stability study and IND application, etc. for your neutralizing antibody.

We are ready to provide the following assays for your product:

A. Fab activity assays. It is for the quality control, lot release and stability study of the product and method qualification is required. We have developed one RBD-based ELISA binding assay and one cell-based neutralization ELISA assay for Fab activity analysis according to the requirement of NMPA/FDA IND application. The method qualification will follow the guidance of USP<1033> Biological Assay Validation, which usually includes robustness, specificity, accuracy, precision, linearity and range.

MOA of SARS-CoV-2 Binding Assay (ELISA)

Binding of His-RBD protein and neutralizing antibody.

Case Study

Note：

ACE2-Fc was used as reference standard (RS).
Both of RS and QC (quality control) were ACE2-Fc.

MOA of SARS-CoV-2 Neutralizing Assay (Cell-based ELISA)

(A) Binding of His-ECD protein and HeLa/ACE2 cells.
(B) Neutralization of ECD-HeLa/ACE2 binding by neutralizing antibody.

Case Study

Note：

ACE2-Fc was used as reference standard (RS).
Both of RS and QC (quality control) were ACE2-Fc.
Human IgG1 (hIgG1) was used as a negative control.

B. Pseudo-virus neutralization assay. The neutralizing activity to protect target cells from being infected is the most important biological characterization of the neutralizing antibody. ProBio has developed a pseudo-virus neutralization assay according to the mechanism of action (MOA) of neutralizing antibodies as well as the SARS-CoV-2 infection.

C. Fc activity assays. The Fc activity is also the biological characterization of the product and also necessary in IND application. ProBio has developed related assays and only needs to verify the assay before sample testing, whereas full method qualification is not required. The assays include ADCC, CDC, and ELISA binding to Fc receptors (CD16a, 158V; CD16a, 158F; CD32a, 131H; CD32a, 131R; CD64; C1q; FcRn).