Definition: method to measure the amount of a substance using an
antibody against the substance for specificity and a radioactive
label for detection and measurement. Radioimmunoassay Definition
- A highly sensitive and specific assay method that uses the
competition between radiolabeled and unlabeled substances in an
antigen-antibody reaction to determine the concentration of the
unlabeled substance; it can be used to determine antibody
concentrations or to determine the concentration of any
substance against which specific antibody can be produced.
Abbreviated RIA (source: NDI Foundation). Radioimmunoassay (RIA)
from Wikipedia - a scientific method used to test antigens (for
example, hormone levels in the blood) without the need to use a
bioassay. It involves mixing known quantities of radioactive
antigen (frequently labeled with gamma-radioactive isotopes of
iodine attached to tyrosine) with antibody to that antigen, then
adding unlabeled or "cold" antigen and measuring the amount of
labeled antigen displa