title: The preparation of a new 57cobalt-labelled thyroxine for use in single/dual radioimmunoassay techniques.
abstract: The preparation of L-thyroxine labelled with 57cobalt for use as a second tracer in dual radioimmunoassay techniques for different biological molecules is described. The labelling procedure was monitored by paper chromatography and polyacrylamide gel electrophoresis; a yield of 42 +/- 10% (mean +/- 1 SD) was achieved in a total of 39 conjugation reactions. The method was optimized in terms of pH, reaction completion time, reactant concentration, and solubility of the tracer. A radioimmunoassay for thyroxine in human serum was developed utilizing this tracer, and this compared favorably with an established technique in which 125iodine was used as the tracer (n = 71, r = 0.91, y = 0.988 x - 1.93).
authors.affiliation: Department of Biochemistry, Faculty of Science, Kuwait University, Safat.
authors.forename: S
authors.initials: S
authors.lastname: Al-Awadi
authors.forename: M
authors.initials: M
authors.lastname: Hassan
authors.forename: K
authors.initials: K
authors.lastname: Adham
authors.forename: H
authors.initials: H
authors.lastname: Abdul-Dayem
mesh_terms: D000937:Antigen-Antibody Reactions; D002854:Chromatography, Paper; D003037:Cobalt Radioisotopes; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006980:Hyperthyroidism / Q000097:blood; D007037:Hypothyroidism / Q000097:blood; D011863:Radioimmunoassay / Q000379:methods*; D012015:Reference Standards; D012995:Solubility; D013974:Thyroxine / Q000378:metabolism* / Q000592:standards
chemical_list: D003037:Cobalt Radioisotopes; D013974:Thyroxine