Biomaterial Database

High-performance assays of small molecules: enhanced sensitivity, rapidity, and convenience demonstrated with a noncompetitive immunometric anti-immune complex assay system for digoxin. 1994

C H Self, and J L Dessi, and L A Winger

Department of Clinical Biochemistry, Royal Victoria Infirmary, Newcastle upon Tyne, UK.

We report the first clinical application of a noncompetitive immunometric assay system that provides advantages for the rapid and robust assay of small molecules similar to those realized for larger molecules with two-site immunometric assays. This anti-immune complex assay is based on the interaction of a receptor such as a primary antibody with its ligand, such that new binding sites, recognizable by a secondary antibody, are formed. In this report the system is applied to the measurement of digoxin in serum. Utilizing an anti-complex antibody that recognizes a digoxin-bound primary antibody with affinity > 2000-fold over its binding to the primary antibody alone, we show that this anti-complex assay system provides a high-performance assay for serum samples, being conveniently simple (immobilized primary antibody binds digoxin and then labeled secondary antibody so that when excess unbound label is washed away the immunometric readout reflects the digoxin concentration), rapid (incubation time 1-10 min), sensitive (detection limit 30 ng/L), precise (3-4% within-run CV, 1-8% total CV), and free from interference from digoxin-like immunoreactive factors.

UI	MeSH Term	Description	Entries
D007118	Immunoassay	A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.	Immunochromatographic Assay,Assay, Immunochromatographic,Assays, Immunochromatographic,Immunoassays,Immunochromatographic Assays
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011786	Quality Control	A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)	Control, Quality,Controls, Quality,Quality Controls
D004077	Digoxin	A cardiotonic glycoside obtained mainly from Digitalis lanata; it consists of three sugars and the aglycone DIGOXIGENIN. Digoxin has positive inotropic and negative chronotropic activity. It is used to control ventricular rate in ATRIAL FIBRILLATION and in the management of congestive heart failure with atrial fibrillation. Its use in congestive heart failure and sinus rhythm is less certain. The margin between toxic and therapeutic doses is small. (From Martindale, The Extra Pharmacopoeia, 30th ed, p666)	Digacin,Digitek,Digoregen,Digoxina Boehringer,Digoxine Nativelle,Dilanacin,Hemigoxine Nativelle,Lanacordin,Lanicor,Lanoxicaps,Lanoxin,Lanoxin-PG,Lenoxin,Mapluxin,Boehringer, Digoxina,Lanoxin PG,Nativelle, Digoxine,Nativelle, Hemigoxine
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000888	Antibodies, Anti-Idiotypic	Antibodies which react with the individual structural determinants (idiotopes) on the variable region of other antibodies.	Anti-Antibodies,Anti-Idiotype Antibodies,Antibodies, Internal Image,Antigamma Globulin Antibodies,Antiglobulins,Anti Antibodies,Anti-gamma Globulin Antibodies,Anti Idiotype Antibodies,Anti gamma Globulin Antibodies,Anti-Idiotypic Antibodies,Antibodies, Anti,Antibodies, Anti Idiotypic,Antibodies, Anti-Idiotype,Antibodies, Anti-gamma Globulin,Antibodies, Antigamma Globulin,Globulin Antibodies, Anti-gamma,Globulin Antibodies, Antigamma,Image Antibodies, Internal,Internal Image Antibodies
D000911	Antibodies, Monoclonal	Antibodies produced by a single clone of cells.	Monoclonal Antibodies,Monoclonal Antibody,Antibody, Monoclonal
D000918	Antibody Specificity	The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.	Antibody Specificities,Specificities, Antibody,Specificity, Antibody