11.2.210-11 · Infectious Disease and Immunity

Making Monoclonal Antibodies — Cambridge AS & A Level Biology 9700 Revision Notes & Topical Questions

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📚 Cambridge AS & A Level Biology 9700 Hub / Topical Revision

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11.2.2 Making Monoclonal Antibodies — CAMBRIDGE AS & A LEVEL BIOLOGY 9700 — REVISION NOTES notes: Describe how monoclonal antibodies are produced from hybridoma cells and evaluate the technique.Polyclonal — when an animal is infected or immunised, many B cell clones respond becau…

Plasma cells
Myeloma cells
Immunisation
Purification
Bioreactors
Conditions

Part 1 of 9Monoclonal and polyclonal antibodies

Polyclonal

Polyclonal when an animal is infected or immunised, many B cell clones respond because the antigen has several epitopes,
- giving a mixture of antibodies.

Monoclonal

Monoclonal a population of identical antibodies made by a single clone of plasma cells, all binding the same epitope.

Value

Value this uniform specificity makes them very useful in medicine and research.

Part 2 of 9The problem solved by hybridomas

Plasma cells

Plasma cells they do not survive long in culture.

Myeloma cells

Myeloma cells cancerous B cells divide indefinitely but do not make useful antibody.

Solution

Solution the technique combines both properties.

Part 3 of 9Cell properties

Cell	Property
B lymphocyte (plasma cell)	Makes one specific antibody but divides only a limited number of times in culture
Myeloma cell	Divides rapidly and indefinitely but does not make the required antibody
Hybridoma	Makes the specific antibody and divides indefinitely

Part 4 of 9Production steps

Immunisation

Immunisation inject a mouse with the antigen so its B cells make plasma cells.
- (for example a protein from a cancer cell or pathogen)

Isolation

Isolation remove the spleen and collect B lymphocytes (plasma cells).

Fusion

Fusion fuse the B cells with myeloma (tumour) cells using polyethylene glycol or an electric pulse to make hybridoma cells.

Selection

Selection grow the mixture in a selective medium in which unfused myeloma cells and unfused B cells die.

Screening

Screening separate hybridomas into individual wells and test the culture fluid of each for antibody that binds the antigen.

Cloning

Cloning select a hybridoma making the correct antibody and grow it in large fermenters (or in mice).

Purification

Purification harvest the antibody and purify it from the culture fluid.

Part 5 of 9Large-scale production

Bioreactors

Bioreactors hybridomas grow under sterile conditions and antibody is secreted into the medium, so it can be collected continuously.

Purification

Purification affinity chromatography passes the medium through a column carrying the antigen or an antibody-binding protein.
Only antibodies of the required specificity remain and are later released.

Conditions

Conditions a supply of nutrients and oxygen, a constant temperature (about 37 °C) and pH, and removal of waste.

Quality control

Quality control each batch is tested to confirm that it binds only its target, and is pure and uncontaminated.

Part 6 of 9Why the antibodies are identical

Clone

Clone all antibodies come from one clone, so they are genetically identical and bind exactly one epitope.

Mitosis

Mitosis hybridomas divide by mitosis to give identical cells.

Cell roles

B cells give specificity, myeloma cells give immortality, and the selective medium removes cells lacking both properties.

Part 7 of 9Humanised antibodies

Mouse antibodies

Mouse antibodies they can cause an immune reaction in humans because they are recognised as foreign.

Humanised antibodies

Humanised antibodies a mouse variable region is joined to a human constant region.

Fully human antibodies

Fully human antibodies now produced by newer techniques.

Benefit

Benefit they are safer and last longer in patients.

Part 8 of 9Evaluation

Advantages

Advantages very high specificity, a constant supply of identical antibody and the ability to target any antigen.

Disadvantages

Disadvantages the technique is complex and expensive, uses animals and may cause side effects or immune reaction.
- (ethical concerns)

Maintenance

Maintenance the tumour-derived hybridoma line must be maintained carefully.

Part 9 of 9More from the specification

1Monoclonal antibody binding of toxins

Monoclonal antibody binding of toxins hybridoma clones synthesize monospecific monoclonal antibodies engineered to bind and neutralize lethal bacterial toxins.

2Active vs Passive Immunity

Active immunity develops when a person is exposed to foreign antigens on pathogen surfaces, stimulating clonal selection of B-cells and production of memory cells,
whereas passive immunity provides rapid, short-term resistance through direct transfer of external antibodies into blood.

3Vaccines and Immunological Memory

Vaccines introduce attenuated pathogens, toxoids,
or isolated surface antigens, triggering a primary immune response and establishing long-lived memory B and T cells that protect against infectious disease.

4Monoclonal Antibody Production Method

Monoclonal antibodies are produced by fusing isolated antigen-sensitised spleen B-lymphocytes with immortal myeloma cells to form hybridomas,
which are screened and cultured to yield identical antibodies.

5Diagnostic and Therapeutic Targeting

Because monoclonal antibodies bind with high specificity to a single unique epitope on a cell surface or circulating toxin, they are utilized to identify pathogen types, detect hCG in urine,
and deliver targeted cancer treatments.

6Receptor protein

Protein on the postsynaptic membrane that binds neurotransmitter.

7Vaccine

Harmless antigen preparation that induces memory cells.

8Vaccination

Introducing a weakened pathogen's antigens to produce memory cells.

9Disease

A condition in which part of the body does not function properly.

10Toxin

A poison released by bacteria.

11Active immunity

Immunity from making your own antibodies and memory cells.

12Passive immunity

Short-term immunity from antibodies given by another individual.

13Memory cell

A lymphocyte that keeps instructions for making a specific antibody.

14Secondary response

The rapid, large response on re-exposure to an antigen.

Key terms

Term	Meaning
Monoclonal antibody	Identical antibodies from one clone, all binding the same epitope.
Polyclonal antibodies	A mixture of antibodies from many B cell clones.
Hybridoma	A fused plasma cell and myeloma cell that divides indefinitely and makes one antibody.
Myeloma cell	A cancerous B cell that divides indefinitely.
Selective medium	A culture medium in which only the wanted cells survive.
Humanised antibody	A mouse antibody modified to carry human constant regions.

Avoid these mistakes

Saying plasma cells divide indefinitely in culture — they divide only a limited number of times.

Saying monoclonal antibodies come from many clones — they come from a single clone.

Saying unfused cells survive in the selective medium — they die.

Saying mouse antibodies are always safe in humans — they can cause an immune reaction.

Last updated: 15 October 2026