monoclonal antibody

• 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


  A stick containing monoclonal antibodies (mAbs) specific to hCG: mAbs attached to a blue bead (free to move), mAbs fixed to the test stick
• What happens to the test stick 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

  
• What happens to the test stick if the pathogen is not present


  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
• Why monoclonal antibodies can be used to target cancer cells


  Cancer cells have specific antigens called 'tumour markers' on their membranes, mAbs are specific to one type of antigen so can be targeted to 'tumour markers' without damaging other 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 that use 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