RIA

Question 1

What is an RIA?

Answer 1

• This is a techniques which determines the antibody levels by introducing an antigen labelled with a radioisotope and measuring the subsequent radioactivity of the antibody component

Question 2

What are RIA tests used for?

Answer 2

• Drug test
• Hepatitis
• Early cancer detection
• Growth hormone levels

Question 3

How does the RIA test work?

Answer 3

• A known quantity of an antigen is radioactively labelled and mixed with a known quantity of the antibody
• The 2 then bind together
• A sample from a patient containing an unknown quantity of the same antigen is added
• This causes the unlabelled antigen from the patient to compete with the labelled antigen to form the antigen-antibody complex

Question 4

What are the factors that effect the result?

Answer 4

• Human antibodies may interfere with an RIA and can react either positively or negatively with the immunoassay reagents to give a false result

Question 5

What is the purpose of this test?

Answer 5

• It is used to measure the low levels of antigens by the use of antibodies

Question 6

what are the limitations of RIAs?

Answer 6

• It is risky working with radioactive substances
• The equipment and reagents which are used are expensive