Topic 3 - Infection and Response - Monoclonal Antibodies

Question 1

What are monoclonal antibodies?

Answer 1

1. Identical anibodies
2. They are proteins produced to target specific cells or chemicals in the body

Question 2

How are monoclonal antibodies made?

Answer 2

1. A mouse is injected with a chosen antigen.
2. B-lymphocytes (that do not divide easily) taken from the mouse are fused with tumour cell (that divides really easily) from lab.
3. This makes a hybridoma.
4. Sinngle Hybridoma cells divide quickly to produce lots of clones that produce the same antibodies.
5. These antibodies are collected and purified.
6. They are monoclonal antibodies - antibodies produced from a single clone of cells.

Question 3

How are monoclonal antibodies used in pregnancy tests?

Answer 3

0. A hormone called HCG is found in the urine of women only when they are pregnant.
1. The bit of the stick where you wee has some monoclonal antibodies specific to the hormone with blue beads attached.
2. The test strip has more monoclonal antibodies specific to HCG that are fixed so they can’t move.
3. If you are pregnant, the hormone binds to the antibodies on the blue beads. The urine moves up the stick, carrying the hormone and the beads. The beads and hormone bind to the antibodies on the strip. The blue beads get stuck on the strip, turning it blue.
4. If you aren’t pregnant, the urine still moves up the stick carrying the blue beads but there is nothing to stick the blue beads onto the test strip. This means it doesn’t go blue.

Question 4

How are monoclonal antibodies used to treat diseases?

Answer 4

1. You can make monoclonal antibodies that will bind to specific cells in the body.
2. You can make monoclonal antibodies bind to the tumour markers on cancer cells.
3. An anti-cancer drug can be attached to these monoclonal antibodies. This might be a radioactive substance, a toxic drug or a cemical which stops cancer cells growing and dividing.
4. The antibodies are given to the patient through a drip.
5. The antibodies specifically target because they only bind to the tumour markers.
6. The drug kills the cancer cells but not the normal body cells.
7. Monoclonal antibodies can also be used to block receptors on the surface of cancer cells to stop the cells growing and dividing.

Question 5

How are monoclonal antibodies used in research?

Answer 5

1. Monoclonal antibodies can bind to hormones and other chemicals in blood to measure their levels.
2. They can test blood samples in labs for certain pathogens.

Question 6

How are monoclonal antibodies used to find specific substances?

Answer 6

1. First, monoclonal antibodies are made that are specific to the molecules you are looking for.
2. The antibodies are then bound to a fluorescent dye.
3. If the molecules are present in the sample you’re analysing, the monoclonal antibodies will attach to them, and they can be detected using the dye under the microscope.

Question 7

How are monoclonal antibodies used in the diagnosis of diseases?

Answer 7

1. Monoclonal antibodies are made to bind to specific antigens found on pathogens, or on blood clots or on cancer cells.
2. These MAB’s may carry markers that make it easier for doctors to see where they have built up.
3. This allows doctors to identify problems before they are seriously affecting a patient’s health.

Question 8

Advantages of monoclonal antibodies?

Answer 8

1. They can be used to treat cancer without affecting normal body cells.
2. Side effects of an antibody-based drug are lower than for standard chemotherapy or radiotherapy.
3. The specificity of MAB’s means they can be used to treat a wide range of conditions.

Question 9

Disadvantages of monoclonal antibodies?

Answer 9

1. They caused more side effects than originally expected (they can cause vomiting, fever and low BP)
2. They are not as widely used or successful than expected when they were first developed