Immunodiffusion Assay: Detecting Precipitates
The question describes a specific type of immunological reaction where antibodies and antigens interact within an agar gel medium, resulting in the formation of a visible precipitate. This characteristic reaction is the hallmark of immunodiffusion assays.
- Mechanism: In immunodiffusion, antibodies and antigens diffuse from separate wells or incorporate into the agar gel.
- Detection: A precipitate line forms in the gel where the diffusing antigen and antibody meet at zones of equivalence (optimal concentration for binding).
- Medium: The reaction occurs within a semi-solid agar matrix, allowing for controlled diffusion.
- Result: The formation and pattern of these precipitate lines are used to identify antigens, antibodies, or quantify their amounts.
Other options are less specific or describe different processes:
- Immunoprecipitation often refers to reactions in solution.
- Immunoaggregation involves clumping of particulate antigens.
- Antibody mediated response is a general immune function.
Therefore, the reaction described, detected by precipitate formation in agar gel, is accurately termed an immunodiffusion assay.
Important Questions from Antigen Antibody Reaction
- If a denatured protein of human origin is injected into a rabbit, antibodies generated will recognize the __________ structure of the protein.
- The lanthanide ion that exhibits color in aqueous solution is
The interaction between an antigen (Ag) and a single-chain antibody (Ab) was studied using Scatchard analysis. The result is shown below.
The affinity of interaction and the total concentration of antibody, respectively, can be determined from
Generally, the coordination number and the nature of the electronic absorption band ($f\rightarrow f$transition) of lanthanide (III) ion in their complexes are, respectively,
- The correct electronic configuration and spin only magnetic moment of $Gd^{3+}$ (at.no. 64) are
