1- RIA's Flashcards
What are RIA’s ?
Radioactive Immunoassays
What are RIA’s used for?
To measure low levels of antigens by the use of antibodies
What is made radioactive?
The known quantity of the antigen
Why is it made radioactive?
So it can be detected and compared to final radioactivity
Which two substances have known quantities?
The radioactive antigen and the antibody
What is added that has an unknown quantity of the same antigen?
The antigen sample from the patient
Why are RIA’s commonly used in clinical laboratories?
They are cost effective and a sensitive technique (have the ability to pick up small differences)
What does the radioactive antigen and known quantity of antibody do?
Specifically bind together
What is the radioactive antigen mixed with?
A known quantity of antibody
What does adding the patient sample cause?
The unlabelled antigen (from the patient sample) to compete with the labelled antigen for antibody binding sites
How is the unknown quantity worked out?
The final radioactivity is compared to the initial radioactivity
Is the final radiation more or less than the initial radiation?
Less than initial
Is the bond between a known quantity of antibody and a known quantity of antigen permanent?
No
When a known quantity of antibody and a known quantity of antigen specifically bind together, what is made radioactive?
The whole thing is radioactive
What does a higher concentration of unlabelled (patient) antigen do?
Displaces more labelled antigen from the antigen - antibody complex
