Production of Monoclonal Antibodies
- Monoclonal antibodies are antibodies that are made by identical immune cells, these identical immune cells are clones of the parent cell
- Antibodies are Y shaped proteins made by lymphocytes, (see Human Defence Systems)
- The antibodies are specific to one binding site on one protein antigen and so are able to target a specific chemical or specific cells in the body
- They are produced by stimulating mouse lymphocytes to make a particular antibody by exposing them to an antigen
The antigen is injected into a mouse and the antibodies combined with a tumour cell to make clones of the antibody
- The lymphocytes are combined with a particular type of tumour cell to make a hybridoma cell
- Tumour cells can divide repeatedly which is why they are used
- The hybridoma cell can both divide and produce the antibody
- Single hybridoma cells are cloned, resulting in many divisions, making high quantities of identical cells that all produce the same antibody
- A large amount of the antibody can be collected and purified ready for use
Exam Tip
The cells produced in this way create only one type of antibody, hence the name ‘monoclonal antibodies’.
Uses of Monoclonal Antibodies
- The cloned antibodies that are produced can be to a specific protein on the cell or a particular chemical
- Monoclonal antibodies have a variety of uses. Some examples include:
- In pregnancy tests – monoclonal antibodies with blue beads attached bind to the HCG hormone (produced during pregnancy) to show a positive test
- To diagnose certain diseases – in laboratories to measure the levels of hormones and other chemicals in blood (such as some cancer proteins), or to detect pathogens
- To treat some diseases: for cancer the monoclonal antibody can be bound to a radioactive substance, a toxic drug or a chemical which stops cells growing and dividing. It delivers the substance to the cancer cells without harming other cells in the body
- To locate blood clots – radioactively labelled monoclonal antibodies are used to bind to proteins in a blood clot. A special camera can then be used to make an image of the radiation and locate the potentially harmful blood clot
Use of monoclonal antibodies table
Exam Tip
You are not expected to recall any specific tests or treatments but given appropriate information, you should be able to explain how they work using the principles of antibody specificity.
You should be able to describe some of the ways in which monoclonal antibodies can be used in the exam. You should also appreciate the power of monoclonal antibodies and be considerate of ethical issues as a result of their production and use.
Advantages & Disadvantages of Monoclonal Antibodies
- Monoclonal antibodies have the potential to make big improvements to diagnosis and treatment and when they were first developed there were hopes for their use to become widespread
- However monoclonal antibodies create more side effects than expected which has hampered their use
Monoclonal antibodies table
