EISA

Question 1

Describe what is meant by monoclonal antibodies

Answer 1

Monoclonal antibodies are antibodies that are identical. They have been produced by the same type of plasma cell, therefore they have the same variable region, and so they’re complimentary to the same antigen.

Question 2

What are the uses of monoclonal antibodies

Answer 2

• Pregnancy tests
• Disease diagnosis tests (including COVID19, and cancer)
• Drugs tests (such as those used to make sure athletes aren’t cheating)

Question 3

Describe what is meant by ELISA

Answer 3

ELISA is the name given to the procedure that uses monoclonal antibodies to detect whether a particular molecule, usually a protein, is present in a sample.

Question 4

What does it mean if the colour of the solution changes in an ELISA

Answer 4

In an ELISA, the colour of the solution will change if the specific molecule we are testing for is present.

Question 5

In an ELISA, the darker the colour of the solution, …

Answer 5

The greater the concentration of that molecule.

Question 6

Describe the process of ELISA tests

Answer 6

• The pre-made ELISA plate contains monoclonal antibodies
• Add the sample to the ELISA plate
• If the antigens are present in the sample, they will bind to the antibodies forming an antibody-antigen complex.
• ELISA plate is washed, which removed unattached antigens, and molecules we are not testing for
• Add a 2nd antibody, but this one has an enzyme attached to it
• This 2nd antibody binds to the same antigen, forming an antigen antibody complex with the antigen
• Wash the plate again, leaving us with just the antibodies that have bound with the antigens
• Add a substrate for the enzyme, forming an enzyme substrate complex. The enzyme changes the colour of the substrate, indicating that the antigen was present in the sample