Biomaterial Database

Two-site immunoradiometric assay of intact salmon calcitonin. 1992

L J Deftos

Department of Medicine, University of California, San Diego.

We developed a two-site immunoradiometric assay (IRMA) of salmon calcitonin (SCT) that detects intact SCT(1-32) and not peptide fragments of the hormone. This was accomplished by using monoclonal antibodies prepared against the peptide fragments SCT(1-11) and SCT(11-32). Two antibodies with specificity for each of the peptides were purified from their respective ascites and evaluated in a two-site format wherein one of the antibodies was adsorbed to polystyrene beads and the other was radioiodinated. In this assay format, the antibody pair detected intact SCT(1-32) but did not react with either SCT(1-11) or SCT(11-32). The sensitivity of the assay could be increased by exchanging the antibodies with respect to bead adsorption and radioiodination. Furthermore, by increasing the incubation time and volume of incubation of sample with the polystyrene-bead-adsorbed antibody, the effective detection limit of the assay could be improved. This assay system can be used to detect intact SCT when the presence of fragments of the hormone might otherwise complicate interpretation of assay data.

UI	MeSH Term	Description	Entries
D007457	Iodine Radioisotopes	Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.	Radioisotopes, Iodine
D008863	Microspheres	Small uniformly-sized spherical particles, of micrometer dimensions, frequently labeled with radioisotopes or various reagents acting as tags or markers.	Latex Beads,Latex Particles,Latex Spheres,Microbeads,Bead, Latex,Beads, Latex,Latex Bead,Latex Particle,Latex Sphere,Microbead,Microsphere,Particle, Latex,Particles, Latex,Sphere, Latex,Spheres, Latex
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D011137	Polystyrenes	Polymerized forms of styrene used as a biocompatible material, especially in dentistry. They are thermoplastic and are used as insulators, for injection molding and casting, as sheets, plates, rods, rigid forms and beads.	Polystyrol,Polystyrene,Polystyrols
D002116	Calcitonin	A peptide hormone that lowers calcium concentration in the blood. In humans, it is released by thyroid cells and acts to decrease the formation and absorptive activity of osteoclasts. Its role in regulating plasma calcium is much greater in children and in certain diseases than in normal adults.	Thyrocalcitonin,Calcitonin(1-32),Calcitrin,Ciba 47175-BA,Eel Calcitonin,Calcitonin, Eel,Ciba 47175 BA,Ciba 47175BA
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000327	Adsorption	The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.	Adsorptions
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
D000939	Epitopes	Sites on an antigen that interact with specific antibodies.	Antigenic Determinant,Antigenic Determinants,Antigenic Specificity,Epitope,Determinant, Antigenic,Determinants, Antigenic,Specificity, Antigenic