Monoclonal vs Polyclonal Antibody Production - Explained Step by Step
Antibody-based therapeutics have reshaped modern medicine. With demand soaring, choosing the appropriate production path can save months and millions.
According to Grand View Research, the global therapeutic antibody market will surpass US $2.21 billion by 2030.
Based on our expertise in monoclonal antibody production, let’s take a look at how each antibody type is produced, contrasts their timelines, costs, and use-cases, and ends with clear next steps to keep your project moving.
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Why Antibodies Matter in Modern Biologics
Antibodies are Y-shaped proteins produced by a type of specialized white blood cell called a “B-cell.” Antibodies recognize and bind to unique structures called antigens found on pathogens such as viruses, bacteria, or rogue cells. By binding to those antigens, antibodies mark pathogens to be neutralized or destroyed by other immune cells.
Antibodies are the body’s natural defence system and by engineering them scientists develop treatments that find disease markers with laser precision.
An epitope is the specific region or sequence on an antigen to which an antibody binds. Monoclonal antibodies recognize a single epitope, while polyclonal antibodies can bind to multiple different epitopes on the same antigen.
Over the past decade, antibodies have evolved from niche biologic solutions to mainstream drugs. In 2024, the U.S. Food and Drug Administration (FDA) approved 50 new drugs, of which 13 were monoclonal antibodies (mAbs). This means antibody-based therapies represented 26% of all new drug approvals that year - a record-setting amount.
The surge of antibody-based drug therapies isn’t just about approvals. The average first-year sales for antibody drugs are now triple those of small-molecule launches, proving how quickly physicians adopt these highly targeted therapies once they hit the market.
Antibodies power an entire ecosystem of diagnostics and research tools, as well as direct-to-consumer products. Many rapid diagnostic tests, like at-home pregnancy kits and COVID-19 antigen tests, are examples of a "sandwich assay" that uses a pair of monoclonal antibodies to display a positive result.
How Monoclonal Antibodies Are Produced
Monoclonal antibodies (mAbs) are laboratory-made proteins designed to latch onto one specific target—the “mono” in their name. Because they act with sniper-like precision, they’ve transformed treatment for cancer, autoimmune disorders and even infectious diseases like COVID-19.
Monoclonal antibodies (mAbs) are homogeneous; every molecule binds the same epitope on an antigen with identical affinity. That uniformity delivers consistent potency and safety—key for FDA or EMA approval.
1. Antigen Selection and Injection
Scientists first identify the specific substance (often a protein from a virus, cancer cell, etc.) called an antigen - the target they want the antibodies to recognize.
This antigen is injected into a small mammal - typically a mouse. The animal’s immune system recognizes the antigen as foreign and launches a defense - a humoral immune response. This creates many different kinds of antibodies against the antigen.
2. Harvesting Antibody-Producing Cells
After several weeks, the mouse's immune system has produced B-cells that make antibodies against the antigen.
Each B-cell is like a tiny locksmith that makes a specific antibody (a key). Some keys are a perfect fit, while others are just okay. After a few weeks, the mouse has an army of these B-cells. The most effective ones are often found in the spleen.
After a sufficient immune response is confirmed by testing the mouse for antibodies against the antigen, scientists remove the spleen from the animal.
3. Cell Fusion
B-cells cannot survive or divide for long outside the body - as in a lab dish. To solve this, B-cells are fused with immortal myeloma cells - cancer cells that can grow indefinitely in the lab).
The resulting hybrid cell is called a “hybridoma” - a hybrid cell that has the best of both worlds. It has the B-cell's ability to produce one specific antibody and the myeloma cell's ability to live and divide in a lab.
4. Selection of Hybridomas
Not all fusions are successful. Scientists use a special selection medium (called HAT medium) so only hybridoma cells (not regular B-cells or myeloma cells) can survive and grow.
Each surviving hybridoma clone comes from a single B-cell and produces only one specific type of antibody… which is why we call them “monoclonal.”
Each hybridoma clone is tested to find out if it produces an antibody that binds specifically to the original antigen.
Scientists do this using techniques such as ELISA (a special test where the antibody's ability to recognize the antigen is measured).
5. Cloning and Expansion
The best hybridoma cells - meaning those producing the most effective antibody - are cloned (often by diluting and growing single cells in separate wells).
Selected clones are grown in large cultures to produce bigger quantities of the monoclonal antibody.
6. Purification
The antibodies made by the hybridoma cells are collected from the culture medium (liquid in which the cells grow). Antibodies are purified using various methods so that only the desired monoclonal antibody remains.
7. Characterization and Testing
The purified antibody is tested further to make sure it is specific, effective, and safe for its intended use (e.g., research, diagnosis, therapy).
How Polyclonal Antibodies Are Produced
Polyclonal antibodies (pAbs) are a mixed population that binds to multiple epitopes on the same antigen. That boosts signal in diagnostics and provides wider neutralisation in anti-toxin therapies.
Let's return to our lock and key analogy. With monoclonal antibodies, the goal was to make a massive supply of one single, perfect key for a specific lock. With polyclonal antibodies, the goal is different.
Imagine the same lock (our disease-causing molecule), but instead of making one perfect key, we want to create an entire toolbox full of tools and key that all contribute to opening the same lock. Some might fit the keyhole, others might grip the outside casing, and others might block its ability to lock again. Together, they work as a versatile team to disable the lock.
Polyclonal antibodies are this toolbox. The production process harnesses the body's natural, powerful, multi-pronged immune response.
1. Antigen Selection and Injection
This begins in the same way as in the maBs example above. Scientists first identify the specific antigen and inject it into an animal to generate a humoral immune response.
The difference is that for the development of polyclonal antibodies, the antigen may be injected into a wider range of selected animals - frequently a rabbit, goat, sheep, or sometimes even a horse.
To increase the animal’s antibody production, scientists may give several booster injections of the antigen over a few weeks. This amplifies the immune response and ensures a higher concentration of antibodies in the animal’s blood.
2. Immune Response and Antibody Production
Over several weeks, the animal receives booster injections to maximize its immune response. Scientists periodically take small blood samples to measure the level (or "titer") of antibodies being produced.
Unlike monoclonal production, where each antibody is identical, here the animal generates a pool of B-cells, each making its own unique antibody shape.
3. Blood Collection & Serum Separation
Once tests confirm the animal has developed strong antibody levels against the antigen, scientists collect a blood sample—typically several times over the course of a few weeks.
The collected blood is allowed to clot. Then, it is centrifuged (spun at high speed) to separate the serum, the liquid component of blood, away from the cells. Serum contains all the antibodies the animal has made, including those against the antigen.
4. Purification
The collected serum contains many proteins besides the desired antibodies. Purification steps are used to isolate the polyclonal antibodies from other serum proteins, ensuring the final product contains antibodies that specifically bind the target antigen.
The most common method is affinity purification, where the original antigen is used as bait. The serum is passed over a surface coated with the antigen; only the antibodies that recognize the antigen will stick to it. These antibodies are then washed free, resulting in a purified solution containing only the high-affinity antibodies directed against the target.
5. Testing and Characterization
The purified polyclonal antibody preparation is then tested to ensure it reacts strongly with the antigen and is suitable for the intended use (such as laboratory research, diagnostic tests, or therapies).
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Monoclonal vs Polyclonal Antibody Key Differences
Despite being based on similar processes related to immune responses, there are differences in mAbs and paBs production that extend beyond their development process.
Uses for mAbs vs pAbs
Monoclonal antibodies have become the dominant class for targeted therapies in cancer, autoimmune diseases, infectious diseases, and more. Because they are so specific, they can target a particular antigen (like a tumor marker or virus protein) with fewer off-target effects. Antibody-drug conjugates (ADCs) and bispecifics all start as monoclonals.
Polyclonals are more often used for antivenoms, anti-toxins, passive immunotherapy, or rapidly-changing pathogens - all situations where broad neutralisation matters more than clone uniformity.
Speed & Scalability
Monoclonal antibody development is slower and more complex. The process includes sophisticated cell engineering, screening, cloning, and validation steps. Once developed, they are easily scalable for large, consistent production. Batch-to-batch consistency is excellent, which is crucial for drugs and diagnostics that require reproducibility.
In one instance, we performed an accelerated tech transfer for a humanized monoclonal antibody (mAb) that was approaching commercialization - and helped our client reduce the time to Process Performance Qualification (PPQ) by more than 25%! Learn more in our mAbs Tech Transfer Case Study.
Polyclonal antibody development is faster, since it mainly involves immunizing an animal, collecting blood, and purifying the antibodies. However, it can be more challenging to scale with exact reproducibility and consistency. Each batch can vary, depending on the animal’s immune response and individual differences.
Cost to Develop
Monoclonals can be more expensive to develop initially due to the technical complexity and labor involved, but costs even out over time for large-scale, long-term production.
Polyclonals can be less costly and faster to generate, especially for short-term or basic research needs. But, large-scale or longer-term production may not experience the economy of scale of monoclonals.
Approval & Regulation
Monoclonal antibodies have a well-established, structured pathway for regulatory approval, including extensive testing for efficacy, safety, and reproducibility. Many monoclonal antibody therapies are FDA-approved and widely used in medicine.
Polyclonal antibodies also have a history of clinical use - especially in toxin neutralization and immune deficiency therapies. However, approvals are fewer and the regulatory path can be less straightforward due to their variability.
mAb Production at AbbVie
AbbVie’s integrated network offers cell banking, cell culture, downstream purification, and sterile fill-finish. Ready to move from discovery to market? Talk to our mAb experts today.