Isotyping Immunoglobulin ELISA Kits and Multiplex Immunoassays

The various antibodies produced by plasma cells are classified by their isotypes that differ in function and antigen responses. Five major classes or antibody isotypes have been identified in placental mammals: IgA, IgD, IgE, IgG, and IgM (Figure 1 and Table 1). Antibody isotypes are categorized according to differences in their amino acid sequence in the constant region (Fc) of the antibody heavy chains. The antibody isotypes IgG and IgA are further grouped into subclasses (e.g., human IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2) based on additional small differences in their amino acid heavy chain sequences. Determination of individual subclasses is relevant in assessing primary immunodeficiencies or immune responses, especially if the total IgG or IgA concentration is not altered.

Learn more about each isotype: Immunoglobulin Structure and Classes

Figure 1. Annotated diagram of immunoglobulin structure.
 

+++: Very Strong Affinity; ++: Strong affinity; +: Moderate/slight affinity; –: No affinity
 

There are multiple methods that can be used for antibody isotyping and the chosen method will depend on the scale and throughput of antibody production, the nature of results needed (i.e., quantitative versus qualitative analysis), assay costs, detection instrumentation, and technical expertise required. These methods include singleplex and multiplex immunoassays, lateral flow assays, microagglutination titer assays, western blotting, indirect immunofluorescence assay (IIFA), and flow cytometry.

Enzyme-linked immunosorbent assays (ELISA) are among the methods of choice for large-scale investigations and can provide accurate quantitative results. Invitrogen isotyping ELISA kits are a fast, sensitive, and convenient method for quantitation of immunoglobulin isotypes during and after hybridoma development and to assess immune response. The Invitrogen ProcartaPlex antibody isotyping panels enable screening titers of individual immunoglobulin isotypes from serum, plasma, and cell culture supernatant samples using Luminex magnetic bead technology.

Learn more about available products for Antibody Isotyping and Characterization

Hybridoma screening is one of the most important steps in monoclonal antibody development and it is performed at multiple stages of the process to help ensure that the most productive and specific clones are selected for further evaluation. Antibody isotyping provides a powerful tool for hybridoma development allowing for rapid screening at the various development stages of fusion, cloning, and subcloning to characterize each potential clone. With Invitrogen isotyping ELISA and ProcartaPlex assays, you can accurately and specifically identify which heavy and light chain your hybridoma is producing and if it is monoclonal or not.

Immunization with vaccines induces the production of antibodies that provide protection against pathogens. To better understand the effects on the immunogenic properties of a vaccine and its adjuvants, profiling sera and plasma can help provide useful insight into immune response. Since each antibody isotype possesses unique effector functions, the examination of individual antibody isotypes first produced following vaccination can help elucidate or indicate a primary immune response to a vaccine. For example, IgE is characteristic in allergic reactions, and therefore useful during the assessment of an immune response. If there is no allergic reaction, IgE is usually barely above the limit of detection whereas a strong IgE response could be an indicator of acute-onset reactions to the vaccine. IgA and IgM levels also increase early on and wane after a few weeks, but IgG levels are longer lasting for long-term immunity.

Learn more about SARS-CoV-2 Serology Assays

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