AQA GCSE Biology Revision
How Monoclonal Antibodies Are Produced
Learn the production process step by step, then check your recall with flashcards and exam-style questions.
Exam answer
The short version
A mouse is injected with the target antigen. Lymphocytes that make the required antibody are collected and fused with tumour cells to form hybridoma cells. A hybridoma cell that produces the correct antibody is selected and cloned. The cloned hybridoma cells make identical antibodies, which are then collected and purified.
Before the method
What monoclonal antibodies are
Monoclonal antibodies are identical antibodies made from one clone of cells. Because they all bind to the same specific antigen, they can be used to identify or target particular cells and chemicals in the body.
Why hybridoma cells are used
A lymphocyte can make the required antibody, but it does not divide endlessly. A tumour cell can divide again and again, but it does not make the antibody you want. Fusing them creates a hybridoma cell that can both divide and produce the specific antibody, which is why hybridomas are central to this method.
Selection and cloning
After fusion, scientists do not use every hybridoma cell. They select the hybridoma that produces the antibody needed for the target antigen. That selected hybridoma is cloned so every new cell is genetically identical and produces the same antibody. This is what makes the antibodies monoclonal.
How to phrase it in an exam
A strong GCSE answer normally names the antigen, lymphocyte, tumour cell, hybridoma cell and cloning stage. Avoid saying the mouse simply makes monoclonal antibodies. The mouse produces lymphocytes; the monoclonal antibodies are produced after the correct hybridoma cell is selected, cloned and grown.
Production steps
The production process in five steps
- 1A mouse is exposed to the target antigen, so it produces lymphocytes that make the matching antibody.
- 2The lymphocytes are collected and fused with tumour cells to make hybridoma cells.
- 3The hybridoma cells divide quickly and produce one type of antibody.
- 4The best hybridoma cell is selected and cloned, so all the cells make the same antibody.
- 5The monoclonal antibodies are collected and purified for use in testing, diagnosis or treatment.
Key terms
Words to use in your answer
monoclonal
antibodies
Exam focus
This is a Higher tier, Biology-only part of Infection and Response. You usually need to describe the sequence clearly and use words such as antigen, lymphocyte, hybridoma and clone accurately.
Quick check
Can you answer these?
- Why are lymphocytes used in monoclonal antibody production?
- Why are tumour cells used?
- What is a hybridoma cell?
- Why does cloning the hybridoma cell produce identical antibodies?
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