Biomaterial Database

Enzyme immunoassay for free thyroxin. 1982

H H Weetall, and W Hertl, and F B Ward, and L S Hersh

We describe a mathematical model for a single-tube enzyme immunoassay for free thyroxin (FT4), involving use of a thyroxin/horseradish peroxidase (EC 1.11.1.7) conjugate that does not interact with thyroxin-binding globulin. In the presence of serum two populations of unassociated, or free, immunologically active constituents are present: FT4 and the conjugate. The concentrations of the former are determined by the serum constituents and of the latter by the albumin concentration. When a small quantity of antibody is added, it reacts with the variable amount of FT4 and with the constant amount of the conjugate, thus giving a measure of the FT4. We constructed a mathematical model based on thermodynamic binding constants and adsorption data. The model gives satisfactory agreement with the experimental data under a variety of experimental conditions. Results for 19 patients' serum samples demonstrate the validity of the concept.

UI	MeSH Term	Description	Entries
D007124	Immunoenzyme Techniques	Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.	Antibody Enzyme Technique, Unlabeled,Enzyme Immunoassay,Enzyme-Labeled Antibody Technique,Immunoassay, Enzyme,Immunoperoxidase Techniques,Peroxidase-Antiperoxidase Complex Technique,Peroxidase-Labeled Antibody Technique,Antibody Enzyme Technic, Unlabeled,Enzyme-Labeled Antibody Technic,Immunoenzyme Technics,Immunoperoxidase Technics,Peroxidase-Antiperoxidase Complex Technic,Peroxidase-Labeled Antibody Technic,Antibody Technic, Enzyme-Labeled,Antibody Technic, Peroxidase-Labeled,Antibody Technics, Enzyme-Labeled,Antibody Technics, Peroxidase-Labeled,Antibody Technique, Enzyme-Labeled,Antibody Technique, Peroxidase-Labeled,Antibody Techniques, Enzyme-Labeled,Antibody Techniques, Peroxidase-Labeled,Enzyme Immunoassays,Enzyme Labeled Antibody Technic,Enzyme Labeled Antibody Technique,Enzyme-Labeled Antibody Technics,Enzyme-Labeled Antibody Techniques,Immunoassays, Enzyme,Immunoenzyme Technic,Immunoenzyme Technique,Immunoperoxidase Technic,Immunoperoxidase Technique,Peroxidase Antiperoxidase Complex Technic,Peroxidase Antiperoxidase Complex Technique,Peroxidase Labeled Antibody Technic,Peroxidase Labeled Antibody Technique,Peroxidase-Antiperoxidase Complex Technics,Peroxidase-Antiperoxidase Complex Techniques,Peroxidase-Labeled Antibody Technics,Peroxidase-Labeled Antibody Techniques,Technic, Enzyme-Labeled Antibody,Technic, Immunoenzyme,Technic, Immunoperoxidase,Technic, Peroxidase-Antiperoxidase Complex,Technic, Peroxidase-Labeled Antibody,Technics, Enzyme-Labeled Antibody,Technics, Immunoenzyme,Technics, Immunoperoxidase,Technics, Peroxidase-Antiperoxidase Complex,Technics, Peroxidase-Labeled Antibody,Technique, Enzyme-Labeled Antibody,Technique, Immunoenzyme,Technique, Immunoperoxidase,Technique, Peroxidase-Antiperoxidase Complex,Technique, Peroxidase-Labeled Antibody,Techniques, Enzyme-Labeled Antibody,Techniques, Immunoenzyme,Techniques, Immunoperoxidase,Techniques, Peroxidase-Antiperoxidase Complex,Techniques, Peroxidase-Labeled Antibody
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D006735	Horseradish Peroxidase	An enzyme isolated from horseradish which is able to act as an antigen. It is frequently used as a histochemical tracer for light and electron microscopy. Its antigenicity has permitted its use as a combined antigen and marker in experimental immunology.	Alpha-Peroxidase,Ferrihorseradish Peroxidase,Horseradish Peroxidase II,Horseradish Peroxidase III,Alpha Peroxidase,II, Horseradish Peroxidase,III, Horseradish Peroxidase,Peroxidase II, Horseradish,Peroxidase III, Horseradish,Peroxidase, Ferrihorseradish,Peroxidase, Horseradish
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012709	Serum Albumin	A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.	Plasma Albumin,Albumin, Serum
D013974	Thyroxine	The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.	L-Thyroxine,Levothyroxine,T4 Thyroid Hormone,3,5,3',5'-Tetraiodothyronine,Berlthyrox,Dexnon,Eferox,Eltroxin,Eltroxine,Euthyrox,Eutirox,L-3,5,3',5'-Tetraiodothyronine,L-Thyrox,L-Thyroxin Henning,L-Thyroxin beta,L-Thyroxine Roche,Levo-T,Levothroid,Levothyroid,Levothyroxin Deladande,Levothyroxin Delalande,Levothyroxine Sodium,Levoxine,Levoxyl,Lévothyrox,Novothyral,Novothyrox,O-(4-Hydroxy-3,5-diiodophenyl) 3,5-diiodo-L-tyrosine,O-(4-Hydroxy-3,5-diiodophenyl)-3,5-diiodotyrosine,Oroxine,Sodium Levothyroxine,Synthroid,Synthrox,Thevier,Thyrax,Thyroxin,Tiroidine,Tiroxina Leo,Unithroid,L Thyrox,L Thyroxin Henning,L Thyroxin beta,L Thyroxine,L Thyroxine Roche,Levo T,Thyroid Hormone, T4