Monoclonal antibodies serve a double function: block specific protein-protein interactions via their antigen-binding region and engage the immune system via their crystallizable fragment (Fc). Due to these properties, antibodies are important tools in therapy and diagnostics. Moreover, due to their stability and ease of production in optimized systems, they also serve as research tools to investigate important biological questions including pathway analysis and clinical research. Check out other frequently asked questions (FAQs) page about monoclonal antibodies on our dedicated page.

Large-scale applications of monoclonal antibodies

Monoclonal antibodies are one of the most sought-after reagents for a multitude of applications. In their full-length format, antibodies are widely useful for therapeutic applications requiring high specificity, selectivity, and optimal immune system engagement properties. Plus, antibodies are recurrently incorporated as reagents for in vitro diagnostic tests, surveillance, medical devices, and medical imaging.

For therapeutic applications, antibodies may be used in their “naked” form as monoclonal therapies. Moreover, it is increasingly frequent that these antibodies are subject to glycoengineering processes. This is explained by the crucial role of the Fc region in the engagement of the immune system and antibody half-life. For this reason, scientists often tailor glycan distribution and nature to maximize antibody half-life (and thus decrease administration frequency) and modulate the immune response.

Both therapeutic and diagnostic applications require, at some point, large-scale commercial production. For this reason, these antibodies require validation in the final antibody expression system and through characterization including affinity determination, epitope mapping, and stability studies, among others. For these applications, antibodies require approval by regulatory agencies, thus, the complete production process must be fully optimized and defined.

Small and medium-scale applications of monoclonal antibodies

In contrast, monoclonal antibodies are also widely used for a variety of research and monitoring applications. In these cases, since antibodies have the ability to block specific protein interactions by binding to specific targets, they are useful to research:

  • Pathway analysis – by blocking/activating certain components of a given pathway (metabolic, disease, etc.), researchers can unravel the relevance of specific elements for these pathways and thus discover new disease markers, therapeutic targets, etc.
  • Drug mechanism analysis – antibodies can serve as analytical tools in drug development by measuring the immune response (e.g. measuring specific cell abundance) before, during, and after treatments. By combining this information with the genetic and clinical background of patients, clinicians can work on developing precision medicine approaches – matching specific patient types with the most suitable treatment.
  • Quantitative and semi-quantitative analysis – conjugated to specific labels (i.e. enzymatic, fluorescent, etc.), antibodies can be used to measure in a quantitative or semi-quantitative way, the presence of certain substances in complex samples including environmental or even clinical samples. Analytical tests exist in different formats including but not limited to:
    • Western Blot (WB)
    • Immunoprecipitation (IP)
    • Immunofluorescence (IF)
    • Immunocyto- or Immunohistochemistry (for cells or tissues, respectively)
    • Chromatin precipitation (ChIP)
    • Enzyme-linked immunosorbent assay (ELISA)
    • Flow Cytometry (FC)
    • Antibody Microarrays
  • Toxic/pathogen detection – pathogens and toxic pose a serious risk to human health and antibodies are increasingly used in biosensor devices to detect their presence in complex samples. Biosensors allow “on-site” detection by combining biological recognition (when antibodies bind their target ligands) with a physical or chemical signal which are then transformed into a digital signal and subsequently interpreted by a computational readout.

Antibodies for these applications are still sparsely produced in hybridoma cell lines using growth in suspension or the ascites method. However, production is increasingly shifting to recombinant systems including yeast, bacterial, and mammalian.

The choice of an adequate production system remains dependent on the intended application, degree of purity required and expected yields per production batch. Given the wealth of knowledge available regarding recombinant expression in mammalian systems, in many cases, these are still the preferred approach to monoclonal antibody production for multiple applications.

Concluding remarks

Antibodies are the preferred reagents for a multitude of applications. They are better known for their therapeutic properties, but they are also widely useful for other applications including diagnostics, basic research, clinical research, environmental research, analysis, and monitoring.

Due to their selectivity, specificity, stability, and ability to block specific protein-protein interactions, they remain invaluable particularly in clinical research where they are used to discover new disease markers, determine new therapeutic targets, and measure patients’ response to specific treatments.

The most popular applications of antibodies in non-therapeutic analyses are ELISA and Flow Cytometry. However, alternative formats like antibody microarrays and biosensors continue to gain relevance particularly in pathway analysis and monitoring (food/environmental safety) applications, respectively.