1. What are monoclonal antibodies ?
Answer
Identical antibodies produced from a single clone of cells.
2. How does the body respond to foreign antigens ?
Answer
Lymphocytes produce antibodies specific to protein antigens.
3. What type of cell does a lymphocyte need to be combined with to make a cell that produces monoclonal antibodies ?
Answer
A lymphocyte needs to be fused with a tumor cell (such as a myeloma cell).
4. What type of cell produces monoclonal antibodies ?
Answer
A hybridoma cell produces monoclonal antibodies.
5. Explain why monoclonal antibodies are described as "specific".
Answer
Monoclonal 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.
6. The figure below shows the process of producing monoclonal antibodies. Use this figure to complete the following text:
"A specific __A__ is injected into a mouse. The mouse __B__ produce antibodies specific to the antigen. The lymphocytes are combined with a tumour cell to make a __C__ cell. The hybridoma cell is __D__ producing many identical cells that make the same antibody. A large amount of __E__ can be collected and purified."
Answer
7. Describe some ways that monoclonal antibodies can be used in diagnostic tests.
Answer
In pregnancy tests, to measure the levels of hormones (or chemicals) in blood, to detect pathogens, to identify specific molecules in a cell (or tissue) and to target specific molecules for treatment.
8. Pregnancy tests, as shown in the figure below, use monoclonal antibodies to detect the hormone HCG. Explain how a pregnancy test can be used to show that a woman is pregnant.
Answer
Urine moves through the reaction site and the mobile antibodies bind to the HCG hormone in the pregnant woman’s urine. When the urine reaches the results site, the HCG hormone binds to the immobilised antibodies. The antibodies also have blue dye attached so a line appears in the results site to show that the woman is pregnant. The urine travels up to the control site where mobile antibodies from the reaction site bind to the immobilised antibodies and the blue dye on the mobile antibodies gives a line to show that the test is complete.
9. Explain how monoclonal antibodies can be used to treat cancer.
Answer
Monoclonal antibodies can be conjugated with radioactive substances, toxic drugs, or chemicals that inhibit cell growth and division. These antibodies specifically target cancer cells without harming other cells in the body.
10. Herceptin is a targeted cancer drug used as a treatment for breast and stomach cancers. Some of these cancers have large amounts of a protein called HER2, which makes the cancer cells grow and divide. Herceptin works by attaching to HER2 protein. Explain how Herceptin stop cancer cells from growing and dividing.
Answer
Herceptin has a specific shape that allows it to bind to receptors (or antigens) on the surface of cancer cells. As a targeted drug therapy, Herceptin selectively affects cancer cells without damaging healthy cells.
11. Why are monoclonal antibodies not yet widely used ?
Answer
A specific monoclonal antibody must be created for each type of cancer, which is difficult. Monoclonal antibodies can cause more side effects than expected, including allergic reactions, joint and muscle pain, diarrhoea, heart problems, and fatigue.