4.3.2 Monoclonal Antibodies

Question 1

How are monoclonal antibodies are produced

Answer 1

Monoclonal antibodies are produced from a single clone of cells
Tumour cell - cell divides but does not make antibodies
Lymphocyte - makes specific antibodies but cannot divide
Hybridoma - does both

1. Stimulate mouse lymphocytes to produce antibodies by injecting the mice with an antigen.
2. Extract the specific lymphocytes and combine them with a tumour cell to make a hybridoma
3. These specific hybridoma cells are cloned
4. This produces a large number of identical cells that produce the same antibodies in large amounts.
5. Monoclonal antibodies are collected and purified.

Question 2

Uses of monoclonal antibodies: Pregnancy tests

Answer 2

MABs specific to a hormone produced during early pregnancy (HCG) are used
They bind to the hormone, if present in urine, and cause a colour change

If pregnant, urine contains hCG. Urine is applied to the sample pad
Then, hCG binds to mobile antibodies. These antibodies also have an enzyme attached to them
Immobilised antibodies in the test zone bind to hCG. The enzyme on the first antibody changes the test line colour. Excess antibodies bind to immobilised antibodies in the control zone to show the test worked correctly.

Question 3

Uses of monoclonal antibodies: diagnosing disease

Answer 3

MABs specific to the antigens found on the surface of pathogens or cancer cells are used
The MABs are also attached to a marker so that doctors can identify if the specific antigens are present
Allows early detection
These are used in tests for prostate cancer and in lateral flow tests

Question 4

Uses of monoclonal antibodies: measuring and monitoring

Answer 4

MABs can also detect the quantity of a chemical or pathogen

This can be used in testing athletes for performance enhancing drugs or in monitoring the amount of certain hormones in the blood

Question 5

Uses of monoclonal antibodies: research

Answer 5

MABs can be bound to fluorescent dye and can then be used by scientists to detect specific molecules in samples of tissue

Question 6

Uses of monoclonal antibodies: treating disease

Answer 6

MABs can bound to a toxic drug radioactive substance or chemical which stops cells dividing
These MABs will target only specific cells (those with the specific antigen) and so only specific cells will be damaged
This is used in treating some cancers