What is immunodiffusion method?
Immunodiffusion refers to the movement of the antigen or antibody or both antigen and antibody molecules in a diffusion support medium. It is a method of gel immunodiffusion: the solutions deposited in the wells dug in the gel diffuse homogeneously in all directions around the well.
What does the gel of immunodiffusion plate contain?
Radial immunodiffusion plates contain specific antiserum in agarose gel, 0.1M phosphate buffer, pH 7.0, 0.1% sodium azide as bacteriostatic agent, 1ug/ml amphotericin B as an antifungal agent.
What happens during an immunodiffusion test?
Immunodiffusion is a diagnostic test which involves diffusion through a substance such as agar which is generally soft gel agar (2%) or agarose (2%), used for the detection of antibodies or antigen. The commonly known types are: Single diffusion in one dimension (Oudin procedure)
What is the main principle of immunodiffusion?
PRINCIPLE: Immunodiffusion in gels encompasses a variety of techniques, which are useful for the analysis of antigens and antibodies. An antigen reacts with a specific antibody to form an antigen-antibody complex, the composition of which depends on the nature, concentration and proportion of the initial reactants.
Where is immunodiffusion used?
Radial immunodiffusion (RID) is a quantitative test, and is often used in serology laboratories to quantify the concentration of a certain antigen or antibody class in a patient’s serum.
What are the different types of immunodiffusion?
Two immune diffusion techniques are radial immunodiffusion (Mancini method) and double immunodiffusion (Ouchterlony method); both are carried out in a semisolid medium such as agar.
What is gel immunodiffusion method used for?
The agar gel immunodiffusion (AGID) test is used to detect antibodies to Type A influenza group-specific antigens, i.e., the ribonucleoprotein (RNP) and matrix (M) proteins. Therefore, this test will detect antibodies to all influenza A virus subtypes.
Which is the limitation of RID?
The lower limit of sensitivity of RID is approximately 0.5 mg/L. Within limitations, the ring diameter for a given antigen concentration can be increased by reducing the antiserum concentration in the gel.