monoclonal antibodies

• Monoclonal antibodies (mAbs)

  Antibodies that are clones from one parent cell, specific to one type of antigen
• Production of monoclonal antibodies

  1. Specific antigen injected into an animal

  2. B-lymphocytes producing complementary antibodies extracted

  3. B-lymphocytes fused with myeloma cells to form hybridoma cells

  4. Hybridoma cells cultured

  5. Monoclonal antibodies collected and purified
• Uses of monoclonal antibodies

  • Detection of pathogens
  • Location of cancer cells and blood clots
  • Treatment of cancer
  • Used in pregnancy test kits
• Myeloma cells

  Type of tumour cell
• Pregnancy kits test for hCG in urine
• Pregnancy test

  • Contains monoclonal antibodies (mAbs) specific to hCG, attached to a blue bead (free to move) and fixed to the test stick
• How a pregnancy test works if a woman is pregnant


  1. hCG in urine binds to mAbs attached to a blue bead

  2. mAbs with hCG diffuse up dipstick

  3. mAbs fixed to the stick bind to hCG

  4. Blue line forms
• How a pregnancy test works if a woman is not pregnant

  No hCG in urine so a blue line is not formed
• Advantages of using monoclonal antibodies to test for pathogens

  • Specific to one particular antigen
  • Very accurate
  • Quick results
• Tumour markers

  Specific antigens on the membranes of cancer cells
• How monoclonal antibodies can be used to diagnose cancer

  1. mAbs tagged to a radioactive substance

  2. mAbs injected into the patient's bloodstream

  3. mAbs bind to 'tumour markers' on cancer cells

  4. Emitted radiation is detected using a specialised scanner enabling doctors to determine the location of cancer cells
• How monoclonal antibodies can be used to target drugs to cancer cells

  1. mAbs attached to an anti-cancer drug

  2. mAbs injected into the patient's bloodstream

  3. mAbs bind to 'tumour markers' on cancer cells

  4. Anti-cancer drug destroys cancer cells
• Why cancer treatments using monoclonal antibodies are favoured over traditional treatments

  • Radiotherapy and chemotherapy target rapidly dividing cells, damaging healthy cells and producing unpleasant side effects
  • mAbs only target cancer cells, reducing damage to normal cells
• How monoclonal antibodies can be used to locate blood clots

  1. mAbs tagged to a radioactive substance

  2. mAbs target and bind to specific proteins in blood clots

  3. Radiation emitted by mAbs is detected, enabling the location of blood clots to be identified