Monoclonal Antibodies

• What is an antibody?

  A protein produced by lymphocytes that help fight disease by binding onto antigens.
• What is an antigen?

  Protein markers on the surface of a cell that is foreign to the body
• What do antigens stimualte?

  Immune response
• What is a monoclonal antibody?

  An antibody produced by a single clone of cells.
• MABS are specific to one binding site on one protein antigen and so can target specific chemicals or specific cell I the body
• Describe the process of producing monoclonal antibodies.(5)

  1. Mouse is injected with an antigen to stimulate the production of lymphocytes that make specific antibodies
  2. Tumour cells are cultured - they divide and grow endlessly/rapidly.
  3. Lymphocytes are taken from the mouse and fused with the tumour cells forming a hybridoma
  4. Hybridoma cells can divide in a Petri dish and make the identical cells that make the antibody
  5. A large number of the monoclonal antibody can be produced, collected and purified for use
• How are monoclonal antibodies used in laboratories?

  Measure the levels of hormones and other chemicals in blood, or to detect pathogens
• How are monoclonal antibodies used in research?

  Identifying specific molecules in a cell or tissue by binding them with a fluorescent dye
• What are uses of monoclonal antibodies?

  Detection

  Diagnosis

  Research

  Treatment
• Explain how a monoclonal antibody works to treat pancreatic cancer. (3)

  1. Monoclonal antibody is attached to radioactive substance / toxin / drug / chemical
  2. Monoclonal antibody will target antigen on cancer cells
  3. Radioactive substance / toxin / drug / chemical will bind to cancer cells and stop them growing / dividing
• Monoclonal antibodies create more side effects than expected so are not as widely used as everyone hoped, when they were first developed.
• What hormone is present in the urine of all pregnant women?

  HCG
• Explain how the pregnancy test works to show a positive result (6)

  1. As urine passes through the reaction zone
  2. HCG hormone binds to the mobile HCG antibody, that is in the reaction zone
  3. The urine passes up the stick and the HCG hormone binds to the immobilised HCG antibodies in the results zone
  4. The other antibodies that do not attach to HCG
  5. Bind to the antibodies in the control zone
  6. A blue dye appears in both control and results zone - to show a positive result
• Why must there always be one line in a pregnancy test's control window?

  To show that the pregnancy test is working
• What are advantages of monoclonal antibodies?

  Can detect pathogens, pregnancy tests, testing for diseases like herpes, chlamydia and HIV, treating conditions like cancer (Magic bullet)
• What are disadvantages of monoclonal antibodies?


  Very expensive, unwanted side effects, human body is very complicated so we don't know how it will respond