Monoclonal antibodies

• Monoclonal antibodies


  Produced from a single clone of cells
• Producing monoclonal antibodies


  1. Mice injected to stimulate lymphocyte production

  2. Lymphocytes fused with tumour cells to create hybridoma cells

  3. Hybridoma cells divide to make a clone

  4. Monoclonal antibody produced, collected and purified
• Lymphocytes


  • Make antibodies but cannot divide to form clones
• Tumour cells


  • Can divide and grow endlessly
  • Can divide to form clones
• Hybridoma cells


  • A single cell can divide to make a large number of identical cells called a clone
  • All the cloned cells can make the antibody
• Use of monoclonal antibodies


  Specific to a single binding site on a specific protein antigen
• Use of monoclonal antibodies


  • Diagnostic testing
  • Research
  • Treatment
• Monoclonal antibodies can be used to measure the levels of a particular chemical in the blood or to detect pathogens
• Pregnancy test using monoclonal antibodies

  1. Urine applied to test stick

  2. Test stick contains monoclonal antibodies that bind HCG attached to dye

  3. If HCG present, monoclonal antibodies cause dye line to appear

  4. Second control line appears to show test is valid
• Monoclonal antibodies produce more side effects than expected when they were first developed, so they are not yet as widely used as was hoped
• Culturing microorganisms


  1. Bacteria multiply by simple cell division (binary fission)

  2. If they have enough nutrients and the optimum temperature, the number of bacteria can double every 20 minutes
• Steps for culturing microorganisms

  1. Loosen the lid on the bacteria culture bottle and dip the inoculating loop in the culture

  2. Inoculate the agar gel plate by streaking the inoculating loop across the surface of the agar

  3. Close the lid and place the inoculated agar gel plate in an incubator
• Bacteria can be grown in

  • A solution (nutrient broth)
  • Colonies on an agar gel plate
• Good aseptic technique


  • Important for growing uncontaminated cultures of bacteria
• Good aseptic technique and safety

  1. Sterilise culture media and agar before use (kill any unwanted microorganisms)

  2. Wipe bench/table with disinfectant

  3. Pass inoculating loop through a blue Bunsen flame and allow to cool slightly

  4. Lift the lid as little as possible when dipping the inoculating loop

  5. Lift one side of the agar gel plate's lid as little as possible when inoculating the agar

  6. Do not create an airtight seal when taping the lid on

  7. Do not incubate at temperatures higher than 25°C

  8. Incubate plates with the surface of the agar facing downwards

  9. Pass inoculating loop through a blue Bunsen flame and place on a heatproof mat to cool

  10. Wipe bench/table with disinfectant
• Binary fission


  The process by which bacteria multiply by simple cell division
• If bacteria have enough nutrients and the optimum temperature


  The number of bacteria can double every 20 minutes
• Nutrient broth


  A solution in which bacteria can be grown
• Agar gel plate


  A surface on which bacteria can be grown as colonies
• Good aseptic technique


  • Important for growing uncontaminated cultures of bacteria
• Steps for culturing bacteria

  1. Sterilise culture media and agar before use

  2. Loosen the lid on the bacteria culture bottle and dip the inoculating loop in the culture

  3. Inoculate the agar gel plate by streaking the inoculating loop across the surface of the agar
• Inoculating agar gel plate

  1. Seal the lid shut and place the inoculated agar gel plate in an incubator

  2. Do not create an airtight seal when taping the lid on

  3. Do not incubate at temperatures higher than 25°C

  4. Incubate plates with the surface of the agar facing downwards
• Inoculating loop


  Pass inoculating loop through a blue Bunsen flame and place on a heatproof mat to cool
• Preparing the workspace


  Wipe bench/table with disinfectant
• Reasons for culturing microorganisms

  • Prevent anaerobic pathogens growing
  • Reduce growth of human pathogens whose optimum temperature is human body temperature (37°C)
  • Stop condensation from dripping on the agar and spreading contamination
  • Sterilise the inoculating loop
  • Kill any microorganisms on the surface
• Microorganisms are cultured for

  Scientific research and biotechnology applications
• Culture volumes


  Small 5ml flasks to large industrial fermenters containing several thousand litres
• Make sure you can write a definition for these key terms
• Key terms


  • agar gel plate
  • aseptic
  • inoculate
  • binary fission
  • lymphocyte
  • clone
  • monoclonal
  • contamination
  • nutrient broth
  • HCG
  • sterilise
  • hybridoma
• Clone of cells


  Group of identical cells that have formed from a single cell dividing over and over again
• Hybridoma


  Hybrid of a lymphocyte and tumour cell-can divide and grow endlessly, and produce antibodies
• Monoclonal antibodies used in research

  • For locating and identifying specific molecules in cells and tissues
• Monoclonal antibodies used in diagnostic testing

  • For measuring levels of specific hormones or chemicals in the blood or urine, for example, pregnancy tests detect HCG hormone in the urine
• Monoclonal antibodies used to treat cancer


  • For delivering toxic chemicals and drugs directly to cancer cells, limiting their harm to other cells in the body
• Monoclonal antibodies are not yet as widely used as was hoped due to more side effects than were initially expected
• Binary fission


  The process by which bacteria divide
• An inoculating loop should be passed through a blue Bunsen flame before and after use to sterilise it/kill any bacteria
• Culture media that microorganisms can be grown in

  • Nutrient broth solution
  • Agar gel plates
• The lids of agar gel plates and culture bottles should be opened as little as possible to prevent contamination with microorganisms from the air
• Incubation should not be at temperatures higher than 25°C to reduce the chance of human pathogens growing