Radio Immunoassay (RIA)

1. Dr. P. Saranraj
Head
Department of Microbiology
Sacred Heart College (Autonomous)
Tirupattur – 635 601
Tamil Nadu, India
Mobile: +91-9994146964; E.mail:
RADIO IMMUNOASSAY
(RIA)

2. RADIOIMMUNOASSAY (RIA)
 Radioimmunoassay (RIA) is an in
vitro Immunoassay technique used to
measure antigen concentrations
(hormone levels in blood) by use
of antibodies.
 In 1960, S. A Benson and Rosalyn Sussman
Yalow introduced RIA to determine levels of
Insulin – Anti-insulin complexes in Diabetics.
 In 1977, some years after Benson’s death, the
significance of the technique was acknowledged
by the award of a Nobel Prize to Yalow.
 The RIA involves the competitive binding of a
radiolabelled antigen to a high affinity

3. Advantages
 The RIA technique is
extremely sensitive and specific, requiring
specialized equipment.
 RIA remains among the least expensive
methods to perform such measurements.
Disadvantages
 The RIA requires special precautions and
licensing, since radioactive substances are
used.

5. Applications of RIA
 Used in the assay Drugs like Digitoxin,
Morphin, Barbifurate and Amphetonine.
 Analysis of Vitamins like Riboflavin and Folic
acid.
 Analysis of Hormones like Aldosterone, Insulin,
Growth hormone and Thyroxin.