Analysis of Caffeine by Immunoassay - Caffeine: Chemistry, Analysis, Function and Effects - page 226

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In less than 3 hours a batch of 66 samples, assayed in triplicate, can be
analyzed in a single microtitre plate. Bearing in mind that at least two
microtitre plates can be handled in parallel by a trained analyst, the
immunoassay offers a remarkable throughput among available analytical
methods for caffeine quantitation.

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Definition of Words and Terms
Antibody: A biomolecule produced in response to an antigen. It will bind
specifically to the antigen which induced its formation.
Antigen: A molecule that generates an immunological response and reacts with
an antibody and the specific receptor on T and B cells of the immune system.
Carrier: An immunogenic molecule or part of a molecule that is recognized by
T cells in an antibody response. It is usually used coupled to a hapten to induce
immune response toward that hapten. Proteins like bovine serum albumin
(BSA) and keyhole limpet hemocyanin (KLH) are among the most popular
carriers for immunochemistry applications.
Conjugate: A reagent that is formed by covalently coupling two molecules
together, such as a hapten coupled to an enzyme like horseradish peroxidase
(HRP).
Cross-reactivity: The ability of an antibody, specific for one antigen, to also
bind a slightly different antigen.
Epitope: The part of an antigen that contacts the antigen binding site of an
antibody (paratope). Small molecules like caffeine (haptens) are believed to
have a single epitope.
Fc fragment: The portion of an antibody that is responsible for binding to
antibody receptor in cells (in vivo) and binding to the microtitre plate in
immunoassays.
Hapten: A small molecule that can act as an epitope, but is incapable by itself
of triggering an antibody response unless bound to a carrier.
Immunoassay: A binding-based analytical procedure that makes use of the
antibodies' recognition properties to bind a specific analyte.
Immunogenic: Having the ability to stimulate an immune reaction and to
produce specific antibodies against that immunogenic substance.
Immunoglobulins: The serum antibodies, including IgG, IgM, IgA, IgE and IgD.
Immunoglobulin G (IgG): Most abundant antibody in serum and the one
predominantly used in immunoassays.
Monoclonal antibodies: Antibodies produced by a single clone of B cells in the
immune system.

List of Abbreviations
Ab

Antibody

Ag Antigen