Monoclonal Antibodies
Biology: Cambridge International A Level, topic 11.2.2
Monoclonal Antibodies
Monoclonal antibodies are produced from clones (genetically identical copies) of cells (often white blood cells). They are all identical and are complementary to one type of antigen (proteins found on the surface of pathogens).
Target specific cells/chemicals
- Monoclonal antibodies are specific to one binding site (area) on one protein antigen (on the surface of cells).
- This means that monoclonal antibodies target specific chemicals or cells in the body.
Uses of Monoclonal Antibodies
Monoclonal antibodies can be used in different ways. However, they may cause side effects such as fevers, low blood pressure and vomiting when used to treat patients. Because of these side effects, monoclonal antibodies are used less commonly than people first expected.
Pregnancy tests
- Pregnant women produce a hormone called HCG.
- Monoclonal antibodies can be used in pregnancy tests to bind (attach) to the HCG hormone’s antigens.
- If the urine contains HCG, the antibodies bind and this shows that the person is pregnant.
- If the urine does not contain HCG, then the antibodies will not bind to the HCG, showing a negative result.
Identifying chemicals in the blood
- Since monoclonal antibodies are specific to one antigen, they can be designed (created) to identify (find) specific chemicals in the blood.
- For example, they can:
- Identify particular molecules in a tissue or cell by binding to them with a fluorescent dye. Areas in the body with lots of these molecules can be highlighted using the dye.
- Identify the levels of hormones in the blood.
- Be used to test blood samples for pathogens, such as HIV.
Treating diseases
- Monoclonal antibodies can be produced to bind (attach) to target cells in the body, e.g. cancer cells.
- We can attach anti-cancer drugs to the monoclonal antibodies. When they bind to the cancer cells, they can deliver the drugs directly to the tumours.
- This is an effective cancer treatment because the antibodies cannot bind to or damage any normal human body cells (because normal cells will not have the complementary antigens).
Test yourself on Monoclonal Antibodies
Monoclonal antibodies are specific to how many binding sites (areas) on a protein antigen?
Producing Monoclonal Antibodies
What are lymphocytes?
Which of these is NOT a common side effect of monoclonal antibodies?