Explain how monoclonal antibodies are produced in a laboratory. Include in your answer the role of lymphocyte cells and hybridoma cells.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (5 marks)
1. A specific antigen is injected into an animal (e.g. a mouse) to stimulate an immune response.
2. Lymphocytes (B‑cells) are harvested from the animal; these cells produce antibodies that are complementary to the injected antigen.
3. The harvested lymphocytes are fused with tumour (myeloma) cells to create hybridoma cells.
4. Hybridoma cells inherit the tumour cells’ ability to divide indefinitely and the lymphocytes’ ability to produce the specific antibody.
5. Hybridoma cells that secrete the desired antibody are selected and cultured, giving large quantities of identical (monoclonal) antibodies.
2. Lymphocytes (B‑cells) are harvested from the animal; these cells produce antibodies that are complementary to the injected antigen.
3. The harvested lymphocytes are fused with tumour (myeloma) cells to create hybridoma cells.
4. Hybridoma cells inherit the tumour cells’ ability to divide indefinitely and the lymphocytes’ ability to produce the specific antibody.
5. Hybridoma cells that secrete the desired antibody are selected and cultured, giving large quantities of identical (monoclonal) antibodies.
Examiner tips
- Use the exact terms ‘antigen’, ‘lymphocytes’, ‘hybridoma’, ‘monoclonal antibodies’. Show the step‑by‑step flow: antigen → lymphocyte → fusion → hybridoma → selection/culture. Include both key functions of tumour and lymphocyte cells in one point to save marks.
Common mistakes
- Confusing lymphocytes with other immune cells (e.g. macrophages). Omitting the tumour cell role or the selection step. Using vague wording such as ‘produce antibodies’ without specifying monoclonal or hybridoma.
Mark scheme (5 marks)
- A specific antigen is injected into an animal (such as a mouse) to trigger an immune response
- Lymphocyte cells are taken from the animal because they produce antibodies complementary to that antigen
- Lymphocyte cells are fused with tumour cells to form hybridoma cells
- Hybridoma cells can divide continuously (because of the tumour cells) AND produce monoclonal antibodies (because of the lymphocytes)
- Cells producing the correct antibody are selected and cultured to produce large numbers of identical (monoclonal) antibodies
Key terms in this question
monoclonal antibodies · lymphocyte · hybridoma cells
Related
- All WJEC A-Level Biology (Wales) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
More Microbiology questions
- Explain how the human immune system responds when a pathogen enters the body for…
- Malaria is a communicable disease caused by a protist spread by mosquitoes. Expl…
- Describe how aseptic techniques are used when culturing microorganisms in a scho…
- Describe how the human body defends itself against pathogens. Include both non-s…