Monoclonal antibodies — AQA GCSE Biology
How monoclonal antibodies are produced from hybridoma cells and the ways they are used in diagnosis, research and treatment.
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Monoclonal antibodies are antibodies produced from a single clone of cells, specific to one binding site on one protein antigen. Mouse lymphocytes are stimulated to make a particular antibody, then combined with a tumour cell to make a hybridoma cell, which can both divide and make the antibody. Single hybridoma cells are cloned, and the antibody is collected and purified.
Monoclonal antibodies are useful because each binds to one specific antigen. They are used in pregnancy tests, in laboratories to measure hormone levels and detect pathogens, and in research to locate molecules using a fluorescent dye. In cancer treatment they deliver a radioactive substance or toxic drug to cancer cells without harming other cells.
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Quick check questions
What does 'monoclonal' mean?
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Produced from a single clone of cells.
Which two kinds of cell are combined to make a hybridoma cell?
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A mouse lymphocyte and a tumour cell.
Why can a monoclonal antibody target specific cells?
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It is specific to one binding site on one protein antigen.
Give two uses of monoclonal antibodies.
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Any two of: diagnosis such as pregnancy tests, measuring hormones or detecting pathogens in the lab, locating molecules in research, treating diseases such as cancer.
Frequently asked questions
What is a monoclonal antibody?
A monoclonal antibody is an antibody produced from a single clone of cells. It is specific to one binding site on one protein antigen, so it can target a specific chemical or specific cells in the body. Monoclonal antibodies are made by cloning hybridoma cells, which are formed by combining mouse lymphocytes with tumour cells.
How are monoclonal antibodies made?
Mouse lymphocytes are stimulated to make a particular antibody, then combined with a particular kind of tumour cell to make a hybridoma cell. The hybridoma cell can both divide and make the antibody. Single hybridoma cells are cloned to produce many identical cells that all make the same antibody, which is then collected and purified.
How are monoclonal antibodies used to treat cancer?
For cancer treatment, a monoclonal antibody is bound to a radioactive substance, a toxic drug or a chemical that stops cells growing and dividing. The antibody binds only to its specific antigen on the cancer cells, so it delivers the substance to those cells without harming other cells in the body.
How does a pregnancy test work?
A pregnancy test uses monoclonal antibodies that bind to a hormone in the urine. Because each monoclonal antibody binds only to its specific antigen, it attaches to that hormone and causes a visible change on the test. You do not need to recall details of specific tests, but you should explain them using this idea.
What are the disadvantages of monoclonal antibodies?
Monoclonal antibodies create more side effects than expected, and they are not yet as widely used as everyone hoped when they were first developed. They also raise ethical issues, because they are produced using mice, which some people object to. Their main advantage is that they are very specific, targeting one chemical or one type of cell.
Written and checked against the AQA GCSE Biology (8461) specification · Updated October 2026