Monoclonal antibodies Flashcards
What are monoclonal antibodies?
Monoclonal antibodies are antibodies that have the same tertiary structure
What is an antibody?
Antibodies are proteins that have binding sites complementary to certain antigens
What are the uses of monoclonal antibodies?
- Medical treatment
- Medical diagnosis
- Pregnancy tests
What 2 ways can monoclonal antibodies treat cancer?
- Direct monoclonal antibody therapy
- Indirect monoclonal antibody therapy
How does direct monoclonal antibody therapy treat cancer?
- Antibodies specific to the antigens on cancer cells are given to the patient
- These antibodies attach to the antigens on the cancer cells which prevents chemicals from binding to the cancer cells that enable uncontrolled division
How does indirect monoclonal antibody therapy treat cancer?
- Antibodies with anti-cancer drugs attached which are specific to the antigens on cancer cells are given to the patient
- These antibodies will attach to the antigens on the cancer cells meaning that the anti-cancer drugs are delivered directly to the cancer cells and will kill them
Why is using monoclonal antibodies better than treatment such as chemotherapy or radiotherapy?
Monoclonal antibody therapies avoids the destruction of healthy cells so no harmful side effects are experienced by the patients
What tests are used for medical diagnosis?
ELISA tests
hCG is a hormone present in the urine of pregnant women. How do pregnancy tests dectect this using monoclonal antibodies?
- The application area contains antibodies that are complementary to hCG which are bound to a coloured blue bead
- A woman will urinate on the application area and if hCG is present in the urine, the hCG will bind to the antibodies attached to the coloured bead, forming an antigen-antibody complex
- The urine moves up the stick to the test strip, carrying the coloured beads with it
- The test strip contains antibodies complementary to hCG that are immobilised
- If hCG is present, the test strip will turn blue as the immobilised antibodies bind to the hCG that is attached to the mobile antibodies
- If hCG is not present, the coloured beads will pass through the test strip without binding so no blue colour appears
What are the 2 types of ELISA?
- Indirect
Direct
How is an indirect ELISA carried out?
- Antigens are bound to the bottom of a well
- Antibodies from a patient sample specific to that antigen, if present, is added and will bind to the antigens attached to the well
- Wash the well to remove any unbound antibodies
- A secondary antibody with an enzyme attached is added that is complementary to the primary antibody
- Wash the well again to remove any unbound secondary antibodies
- A solution containing the substrate that is complementary to the enzyme attached to the secondary antibody is added and they will react and produce a coloured product
- A colour change indicates the patient has specific antibodies for that specific antigen
How is a direct ELISA carried out?
- Antigens from a patient sample are bound to the bottom of a well
- Antibodies with an enzyme attached that is complementary to the antigen is added
- The well is washed out to remove any unbound antibodies
- A solution containg the substrate complementary to the enzyme attached to the antibody is added
- If the antigens are present, they will bind with the antibody and the enzyme on the antibody will react causing a colour change
What is the difference between an indirect and direct ELISA?
Indirect ELISA’s use two antibodies whereas direct ELISA’s use one antibody
What is an ethical issue of monoclonal antibodies?
Creating monoclonal antibodies require mice to produce
The mouses’ spleen is removed and will therefore die as a result
