Monoclonal Antibodies (OCR Gateway GCSE Biology)

Higher Tier Only

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
  
• 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 quickly and 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 numbers of identical cells that all produce the same antibody
• A large amount of the antibody can be collected and purified ready for use

Higher Tier Only

Monoclonal antibody uses

• The cloned antibodies that are produced can be complementary to a specific protein on the cell or a particular chemical
• Monoclonal antibodies have a variety of uses, some examples include:
  
  • In pregnancy tests
  • In laboratories to measure the levels of hormones and other chemicals in blood (such as some cancer proteins), or to detect pathogens
  • In diagnostic test kits such as
    • Those used commonly in the Covid-19 pandemic (lateral flow tests)
    • The detection of prostate cancer in men by testing for a protein (found in blood and urine) that is associated with the disease
  • In research to locate or identify specific molecules in a cell or tissue by binding to them with a fluorescent dye
  • 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 in a targeted way, without harming nearby cells or cells in other organs and systems

Use of Monoclonal Antibodies Table