06-10-2012, 11:11 AM
RADIOIMMUNOASSAY
RADIOIMMUNOASSAY.pptx (Size: 362.93 KB / Downloads: 91)
DEFINITION:
RIA is a radio analytical technique with high degree of sensitivity and specificity in tracing variety of molecules present in complex matrices
INVITRO DIAGNOSIS TEST FOR ANTIGENS USING RADIO ISOTOPES
Introduction :
This isotopic measuring method was developed in 1959 by two Americans,biophysicist Rosalyn Yalow and physician Solomon A. Berson.
RIA combines the specificity of an antigen-antibody reaction with sensitivity of radioactivity measurements.
It can also be used for detection of pictogram quantities (10−12 g) of biological constituents present in biological fluid.
Procedure for methods
Radio labelling of the Antigen or radio labelled production
Preparation & characterisation of the Antigen [Ligand to be analysed]
Preparation of the Specific Antibody
Development of Assay System or separation techniques
Advantages:
Highly specific: Immune reactions are specific,the greater the specificity of the antiserum, the greater the specificity of the assay.
High sensitivity : Immune reactions are sensitive, Using antibodies of high affinity it is possible to detect a few picograms (10−12 g) of antigen in the tube.
Accuracy and Precision
Disadvantages:
Radiation hazards: Uses radio labelled reagents
Requires specially trained persons
Labs require special license to handle radioactive material
Requires special arrangements for
Requisition, storage of radioactive material
radioactive waste disposal.
Application of RIA:
Analysis of hormones, vitamins, metabolites, diagnostic markers:
E.g. ACTH, FSH, triiodothyronine (T3) and thyroxine (T4), Glucagons, Insulin, Testosterone, vitamin B12, prostaglandins, glucocorticoids,
Therapeutic drug monitoring:
Barbiturates, morphine, digoxin,
Diagnostic procedures for detecting infection :
HIV, Hepatitis A, B etc