Home / ELISpot Serological Assays for Coronavirus Research

ELISpot Serological Assays for Coronavirus Research

Highly Sensitive and Specific B Cell ELISpot Assays

for SARS-CoV-2 IgG and IgM Antibodies.

B Cell ELISpot assays

B Cell ELISpot Assays to Measure the Immune Response to Infection

The antigen-down B cell ELISpot assay is a powerful 96-well assay to study the extent of the immune response to viral infections. The larger the number of spots left by B cells, the stronger the antibody-producing capacity of the immune system. The B cell ELISpot is built with highly sensitive and specific antibodies. When paired with pure and specific SARS-CoV-2 proteins, it becomes a robust and highly sensitive serological assay for SARS-CoV-2 infection.

Investigators at the University of Minnesota utilized R&D Systems ELISpot plates pre-coated with SARS-CoV-2 recombinant proteins to assess IgM and IgG secretion by B cells collected from volunteers (Figure 1).  

A   B   C
B cell ELISpot assay detecting IgG and IgM antibody responses to SARS-CoV-2 infection.   – B cell ELISpot assay detecting IgG and IgM antibody responses to SARS-CoV-2 infection   – B cell ELISpot assay detecting IgG and IgM antibody responses to SARS-CoV-2 infection

 Figure 1 B Cells from a volunteer (1 month post-SARS-CoV-2 infection) were cultured in plates pre-coated with 15 ug/ml of SARS-CoV-2 Spike RBD His-Tag Protein (A), SARS-CoV-2 Spike (Active Trimer) His Protein (B) and SARS-CoV-2 Spike (GCN4-IZ) His Protein (C) at a density of 50,000 cells per well. Reactive spots indicate IgG secretion from cultured B cells. The larger the spot the more robust the IgG secretion. Cells from uninfected volunteers were not reactive (Data not shown).

 

Protocol: B-Cell ELISpot as a SARS-CoV-2 Single Color IgG or IgM Serology Test

B cell ELISpot assay detecting IgG and IgM antibody responses to SARS-CoV-2 infection.

 

R&D Systems IgG and IgM Antibodies are Specific

R&D Systems manufactures highly specific IgG and IgM antibodies. Direct ELISAs are commonly used to evaluate antibody affinity. Figures 2 and 3 demonstrate the specificity of the anti-human IgG (hIG) and anti-human IgM (hIgM) antibodies antibody provided in our B-cell ELISpot assay have a high affinity for hIgG and hIgM, respectively, with limited cross reactivity to other classes of immunoglobulins.

 

Purity data for SARS-CoV-2 antigen protein used in B cell ELISpot assay protocol.

 

click to view larger

   

Purity data for SARS-CoV-2 antigen protein used in B cell ELISpot assay protocol.

click to view larger

  


Figure 2.Data from a direct ELISA indicates that the R&D Systems anti-human IgG antibody included in R&D Systems B cell ELISpot assays is specific for hIgG 1-4 with minimal cross reactivity to hIgA, hIgD, hIgE or hIgM.

   Figure 3. Data from a direct ELISA indicates that the R&D Systems anti-human IgM antibody included in R&D Systems B cell ELISpot assays is specific for hIgM with no cross-reactivity to hIgA, hIgG, hIgG Fc only.


 

High Quality Recombinant Coronavirus Proteins

The data described in figure 1 was generated using high-quality R&D Systems recombinant coronavirus proteins as antigens. The data examples shown below demonstrate the purity (Figure 4) and lot-to-lot consistency (Figure 5) of recombinant SARS-CoV-2 Spike proteins. Download this flyer for a more detailed description of analyses that R&D Systems scientists routinely perform to characterize our antibodies and recombinant proteins prior to their commercial release.

 

Purity data for SARS-CoV-2 antigen protein used in B cell ELISpot assay protocol.    SARS-Cov-2 and ACE-2 binding data from functional ELISA.

 

Figure 4. The purity of Recombinant SARS-CoV-2 Spike RBD His-tag Protein was assessed by SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at the expected molecular weight range of 32-38 kDa. 

  

 

Figure 5. Four independent lots of Recombinant Human ACE-2 His-tag Protein were tested for their ability to bind to Recombinant SARSCoV-2 Spike RBD Fc Chimera Protein in a functional ELISA. The data demonstrates high lot-to-lot consistency across these four lots.

 

Table 1:  Available recombinant coronavirus proteins. The first three proteins were used as antigens in figure 1.

Catalog   Recombinant Protein
10500-CV   SARS-CoV-2 Spike RBD His-Tag Protein
10549-CV   SARS-CoV-2 Spike (Active Trimer) His Protein
10561-CV   SARS-CoV-2 Spike (GCN4-IZ) His Protein
10522-CV   SARS-CoV-2 Spike S1
10523-CV   SARS-CoV-2 Spike RBD
10474-CV   SARS-CoV-2 Nucleocapsid
10521-CV   MERS-CoV Nucleocapsid
10621-CV   MERS-CoV Spike RBD
10600-CV   HCoV-HKU1 Spike RBD
10605-CV   HCoV-NL63 Spike RBD Protein
10612-CV   HCoV-229E Spike RBD Protein
 

Don’t see the specific protein you need? We have a large selection of recombinant coronavirus proteins.

 

Conclusions

R&D Systems B cell ELISpot Assays can be utilized as a sensitive and specific, economical coronavirus serological research tool. Together, R&D Systems B cell ELISpot and recombinant coronavirus proteins can be used in your research to study the immune response to natural SARS-CoV-2 infection or vaccine candidates. When used with high-quality R&D Systems recombinant proteins, you can expect reliable and consistent data over the long term.

 Learn More About ELISpot Assays
 View B Cell ELISpot Assays

 

Additional Resources

Kantaro Quantitative SARS-CoV-2 IgG Antibody RUO Kit
Immunoassays for COVID-19 Research
Luminex Custom Coronavirus Serological Assay
ELISpot Troubleshooting Guide
Dual color ELISpot Assay Principle
Single Analyte ELISpot Assay Principle

 

Featured Content

Featured Content

Immunoassays for COVID-19 Research

Immunoassays for COVID-19 Research

Get the assays you need for fast, accurate detection of key cytokines and antibodies triggered by viral infections like COVID-19

See All Coronavirus Assays

Featured Content

High Sensitivity Immunoassays for Detecting IFN-Gamma in Cytokine Release Syndrome

PDF on IFN-gamma Immunoassays for Cytokine Release Syndrome

Download this application note to see how Quantikine High Sensitivity ELISAs quantify IFN-gamma in serum and plasma.

Download the IFN-Gamma Application Note

Featured Content

Custom Coronavirus Serological Assay

Custom Coronavirus Serological Assay

This custom, antigen-down, Luminex® serological assay distinguishes between SARS-CoV-2 and other coronavirus subtypes!

Download the Application Note

Featured Content

Simple Western Assays for Detection of ACE2 and TMPRSS2, Key Players in SARS-COV-2 Infection

PDF on using Simple Westerns for SARS-CoV-2 Research

Learn how Simple Western assays were used to provide molecular weight information and quantify ACE2 and TMPRSS2 in human cells.

Download the Simple Western Application Note