In immunology and medical research, antibodies are critical in detecting and neutralizing harmful pathogens. Our immune system produces these Y-shaped proteins to target specific invaders, such as bacteria, viruses, and toxins. In scientific research and clinical applications, Monoclonal And Polyclonal Antibodies are two types of antibodies commonly used. They have distinct characteristics and applications, making it essential to understand the key differences between them. In this blog post, we will explore the fundamental disparities between monoclonal antibodies and polyclonal antibodies.
Monoclonal antibodies can be produced in specialized cells through a technique now popularly known as hybridoma technology. They are derived from a single clone of immune cells, typically a single B-cell or a hybridoma cell line. These cells are genetically identical, producing antibodies that are exact copies of one another. The technology was discovered way back in 1975 by Milstein and Kohler who were awarded Nobel Prize later. Monoclonal antibodies have a single epitope, which binds to one specific site on an antigen. They are highly specific targeting a single epitope on an antigen hence have wider application. Immortal cell lines produce monoclonal antibodies, hence batch to batch production lots does not change.
In contrast, polyclonal antibodies are produced by multiple B-cell clones, each recognizing a different epitope on the same antigen. This diversity in origin results in a mixture of antibodies with varying specificities. Polyclonal antibodies are more diverse in their binding capabilities, as they can target multiple sites on an antigen. Polyclonal antibodies are less specific than monoclonal antibodies because they recognize multiple epitopes on an antigen.
This can be advantageous in some cases, as it may increase the chances of binding to the target antigen. However, it can also lead to cross-reactivity with unrelated antigens, potentially causing false-positive results or unintended interactions. Polyclonal antibodies are typically generated by immunizing an animal, such as a rabbit or goat, with the target antigen. The immune response in the animal leads to the production of antibodies from multiple B-cell clones, resulting in a mixture of antibodies with varying specificities. There could be batch-to-batch differences in the production lot.
Once a Monoclonal Antibody is developed against an antigen, the epitope and paratopes are fixed and hence there is fixed specificity. There is no requirement of antigen for further immunization whereas there is a continuous requirement of antigen for immunization when we are producing polyclonal antibodies. This hinders scalability in production. When a scientist is required to develop any application, we need to understand the scope of antibodies and hence understand whether our need is satisfied by polyclonal or Monoclonal
SO HOW DO WE DECIDE IF WE NEED MONOCLONAL OR POLYCLONAL
(Make a Scientis picture thinking monoclonal vs polyclonal)
Sometimes in our experiment, we require tools for exploring whether our interest in protein is present in a sample or not. Can we think if our assay is a one-time, though critical, and the antibody is not available? In that scenario we need to go for Polyclonal Antibody where the timeline is less and our purpose is solved and as a researcher, we support our experiment with pull-down assays such as western blot, ELISA, etc.
However, if our scope of work is the development of some diagnostic assays, Lateral flow rapid card assay, or sandwich ELISA where criticality is not only the detection of antigen but also not detecting noise or background in the assay then we should strictly work with Monoclonal antibody because of its attribute for specificity, scalability and efficacy.
Also Read : Scope of Monoclonal Antibody Drugs
| Antibodies | Pros | Cons |
| Monoclonal Antibodies |
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| Polyclonal Antibodies |
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APPLICATION based decision
| APPLICATION | Polyclonal | Monoclonal |
| ELISA based Diagnostic | Used mostly for detection along with monoclonal as a pair | Used preferably for Coating |
| Lateral Flow Assay | May be used as a coating antibody | Best for Both coating as detection |
| Immunohistochemistry (IHC) | Can be used | preferred |
| Immunoprecipitation (IP) and Chromatin Immunoprecipitation (ChIP) | Can be used | Can be used |
| Western Blot (WB) | Preferred | Preferred if differentiation is required |
| Secondary Antibody | Preferred | Only in critical experiments |
| Flow cytometry and FACS. | Not much Popular | Preferred |
Conclusion:
Monoclonal antibodies and polyclonal antibodies each have their unique characteristics and applications. Monoclonal antibodies are prized for their exceptional specificity and consistency, making them a go-to choice for precision-driven diagnostic and therapeutic applications. On the other hand, polyclonal antibodies offer versatility and cost-effectiveness, making them valuable for initial research and exploratory studies where broad antigen recognition is advantageous.
The choice between monoclonal and polyclonal antibodies depends on the specific requirements of the research or clinical application. In many cases, a combination of both types may be employed to harness the strengths of each. Understanding these key differences is essential for researchers, clinicians, and scientists working with antibodies to make informed decisions and achieve the best results in their work.