title: [The role of binding proteins in radioimmunologic determination of the free thyroxine concentration using thyroxine analog methods: thyroxine immunoextraction versus thyroxine analog immunoextraction].
abstract: Amerlex FT4-analogue one step RIA was investigated to estimate the 125-Iodine thyroxine immunoextraction in sera with normal and abnormal concentrations of binding proteins. The following results were found: Amerlex analogue FT4 RIA equals an equilibrium-immunoassay. Thyroxin-analogue tracer is strongly bound to an albumin (80%). During the assay procedure, there is no analogue binding to serum proteins. If serum and FT4-antibody diluted in an adequate manner, FT4-analogue values in all serum dilution steps are determined identically. FT4-analogue values are influenced only by thyroxine, bound to albumin and/or prealbumin and not by TBG-bound thyroxine. Serum albumin concentration does not influence FT4-analogue values.
authors: Medizinische Universitätsklinik, Graz.
authors: A
authors: A
authors: Passath
mesh_terms: D006801:Humans; D011863:Radioimmunoassay; D013960:Thyroid Function Tests; D013974:Thyroxine / Q000097:blood*; D013975:Thyroxine-Binding Proteins / Q000032:analysis*
chemical_list: D013975:Thyroxine-Binding Proteins; D013974:Thyroxine
vernacular_title: Die Rolle der Bindungsproteine bei der radioimmunologischen Bestimmung der freien Thyroxinkonzentration mit Thyroxinanalogmethoden: Thyroxinimmunextraktion versus Thyroxinanalogimmunextraktion.