Biomaterial Database

Critical analysis of [131I]- and [125I]human thyroglobulin labels for radioimmunoassay use. 1982

M Schlumberger, and A J Van Herle

[125I]- and [131I]thyroglobulin (Tg) tracers obtained by two different oxidation methods, chloramine-T (Chl-T) and lactoperoxidase (LP-ase), were analyzed to assess their suitability in the development of a RIA. Pairs of tracers which were prepared on a single day using these methods with a single source of 131I and 125I were compared. The following conclusions were reached. 1) Both 131I and 125I isotopes, using CHl-T or LP-ase oxidants, produce suitable tracers. 2) [131I]Tg can be used repeatedly for 2 weeks without repurification. 3) [125I]Tg, in contrast, has to be rechromatographed weekly on Sephadex G-200 to maintain assay sensitivity and adequate maximal binding. 4) Under these conditions, 2- or 9-day tracers with either isotope using Chl-T or LP-ase give similar Tg determinations in the serum. 5) The LP-ase-chromatographed 125I tracer seems to lead to higher maximal binding in the assay than the Chl-T-repurified tracer.

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
D007553	Isotope Labeling	Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.	Isotope Labeling, Stable,Isotope-Coded Affinity Tagging,Isotopically-Coded Affinity Tagging,Affinity Tagging, Isotope-Coded,Affinity Tagging, Isotopically-Coded,Isotope Coded Affinity Tagging,Labeling, Isotope,Labeling, Stable Isotope,Stable Isotope Labeling,Tagging, Isotope-Coded Affinity,Tagging, Isotopically-Coded Affinity
D007784	Lactoperoxidase	An enzyme derived from cow's milk. It catalyzes the radioiodination of tyrosine and its derivatives and of peptides containing tyrosine.
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
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
D002700	Chloramines	Inorganic derivatives of ammonia by substitution of one or more hydrogen atoms with chlorine atoms or organic compounds with the general formulas R2NCl and RNCl2 (where R is an organic group).	Chloroamines
D004355	Drug Stability	The chemical and physical integrity of a pharmaceutical product.	Drug Shelf Life,Drugs Shelf Lives,Shelf Life, Drugs,Drug Stabilities,Drugs Shelf Life,Drugs Shelf Live,Life, Drugs Shelf,Shelf Life, Drug,Shelf Live, Drugs,Shelf Lives, Drugs
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013954	Thyroglobulin
D014105	Tosyl Compounds	Toluenesulfonyl compounds with general formula CH3C6H4S(O2)R” widely used to block amino groups in the course of syntheses of drugs and other biologically active compounds.	Toluenesulfonyl Compounds,Compounds, Toluenesulfonyl,Compounds, Tosyl