The immune system of a COVID-19 patient produces antibodies to SARS-CoV-2 within days to a few weeks following viral infection. The immune reaction to COVID-19 produces neutralizing antibodies and generally provides immunity in the event of a second exposure to the virus and also provides a basis for vaccine development. Antibody testing is typically performed using Enzyme-Linked Immunosorbent Assay (ELISA) or related automated immuno-assays. While ELISA has high-throughput capability when automated, it requires several time and labor-intensive steps that lengthen assay time. Testing of Immunoglobulins-IgG, IgM and IgA by ELISA or other immunoassays, requires individual time-consuming assays to be run. Detection requires labeling and the use of additional reagents to report binding of the analyte to the receptor.

Surface plasmon resonance (SPR) biosensors offer a label-free direct measurement platform for rapid quantitative and qualitative characterization of biologically relevant analytes. Presence of specific antibodies in the circulatory system can thus serve as a biomarker of various diseases such as microbial infection, virus infection and autoimmune disease.

  • Measure immune responses from patient serum to known antigens for up to 384 samples using a rapid and automated method.
  • Detect multiple secondaries against the same sample to reduce assay complexity while still gaining more information.
  • Profile the immune response for levels of IgA, IgG and IgM in COVID-19 patient samples.
  • Get profiling results using only two microliters of patient serum.

Here, we describe a high-throughput SPR assay to profile the immune response to SARS-CoV-2 of COVID-19 patients by measuring the IgG, IgM and IgA antibodies binding to the receptor-binding domain (RBD) of the Spike protein.

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Posted by Judicaël Parisot, PhD