monoclonal antibodies

• First Step in production

  Inject a mouse with antigen you want to make antibodies for
• Second step in production

  Remove lymphocytes from the spleen of the mouse
• Third step in production

  Fuse each lymphocyte with a tumour cell to form hybridoma cell (to dive and make antibody)
• Fourth step in production

  Clone hybridoma (force division through mitosis) to create millions of cells to produce the specific antibody
• Fith (final) step in production

  Extract and purify the monoclonal antibodies
• How are they used on humans?

  Injected into person with specific pathogen so mAbs bind to complimentary antigens to attract phagocytes which engulf pathogens to eliminate infection
• Uses (3) of mAbs

  1. Detect presence/abscence/levels of hormones/chemicals/pathogens in bodily fluid (e.g. lateral flow test)

  2. Locate spefic molecules in a cell or tissue

  3. Treat disease (e.g. cancer)
• Name of hormone tested for in pregnancy test (present in early stage pregnancy in urine)

  Human chorionic gonadotrophin (HCG)
• If HCG present in urine in pregnancy test-

  mAbs bind to it resulting in colour change on the test indicating positive
• Steps in using mAbs to identify specific molecules (3)

  1. Attach fluorescent marker to mAb that is complementary to molecule

  2. mAb binds to specific molecule in cell/tissue and fluoresces

  3. Now can see where the particular molecule is in cells/tissues
• Use in cancer treatment (4)

  1. Make mAbs complementary to antigens found on cancer cells

  2. mAbs bind to antigens on cell membrane signalling to phagocytes to engulf and destroy cancer cells

  3. Or they can bind to receptors on cancer cell membranes that normally bind to growth stimulating molecules so stopping growth of tumour

  4. Or can be radioactive or toxic to kill cancer cells
• Advantages-


  Only bind to the specific cell targeted so do not affect healthy cells unlike most drugs or chemo.
• Disadvantages (2)


  1.expensive and time consuming to produce

  2.More side effectst han expected as made from mouse cells