High Sensitivity Assays for IgG, IgM, IgA, and N/S-Proteins

An Enzyme-Linked Immunosorbent Assay (ELISA) is a common biochemical technique that can be used to detect antigens or antibodies, depending on the type of test used. There are several types that have been used in a variety of aspects of COVID19 research, including sandwich-based ELISA and indirect ELISA. The sandwich-based ELISA method is used for the quantitative measurement of soluble proteins in biological fluids. The indirect ELISA method is most suitable for determining total antibody concentrations in a sample.

Current testing for the SARS-CoV-2 virus is limited, and compared to RT-qPCR, ELISA is a less complex procedure that uses more affordable and available equipment. Similarly, antigens and antibodies are considerably more stable than RNA, which reduces the potential of false-negative results. The ability to collect samples from many places in the body (and not restricted to nasal swabs) improves testing accuracy as well.

Sandwich-based ELISA measuring viral antigens could be an alternative to RT-qPCR to detect current infections.

Alternatively, serology measurements rely entirely on a host’s antibody response to the virus rather than detecting the virus itself. Indirect ELISA has been used to 1) diagnose patients who are more than 1 week post symptom onset, 2) determine potential immunity and risk of infection, 3) advance contact tracing, and 4) understand the extent of COVID19 spread and immunity in communities through epidemiological studies that are particularly important for fighting COVID-19 while minimizing economic impact.


Indirect ELISA - In-Vitro Diagnostic Use IVD 35% off through July 31!

Catalog # Antibody Detected Antigen Sample Type Quantitative / Semi-Quantitative
IEQ-CoVN-IgG IgG N protein Serum Quantitative
IEQ-CoVS1RBD-IgG IgG S1 RBD protein Serum Quantitative

Indirect ELISA - Research Use Only (RUO) 35% off through July 31!

Catalog # Antibody Detected Antigen Sample Type Quantitative / Semi-Quantitative
IE-CoVN-IgA IgA N protein Serum/Plasma Semi-Quantitative
IE-CoVS1RBD-IgA IgA S1 RBD protein Serum/Plasma Semi-Quantitative
IEQ-CoVS1RBD-IgA-DBS IgA S1 RBD protein Dried Blood Quantitative
IE-CoVN-IgM IgM N protein Serum/Plasma Semi-Quantitative
IEQ-CoVS1RBD-IgM IgM S1 RBD protein Serum Quantitative
IEQ-CoVS1RBD-IgM-DBS IgM S1 RBD protein Dried Blood Quantitative
IEQ-CoVN-IgG-DBS IgG N protein Dried Blood Quantitative
IEQ-CoVS1RBD-IgG-DBS IgG S1 RBD protein Dried Blood Quantitative

Sandwich-based ELISA - Research Use Only (RUO)

Catalog # Antigen Detected Sample Type Sensitivity Quantitative / Semi-Quantitative
ELV-COVID19N N protein Serum/Plasma 0.07 ng/mL Quantitative
ELV-COVID19S2 S protein Serum/Plasma 2.7 ng/ml Quantitative


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