A Sensitive and Precise Method for Estimation of Free Thyroxine in Serum as a Thyroid Function Test Using L-Thyroxine-125I

Autor: Y. M. Megahed, M. F. Abdel-Wahab
Rok vydání: 1974
Předmět:
Zdroj: Isotopenpraxis Isotopes in Environmental and Health Studies. 10:255-258
ISSN: 0021-1915
DOI: 10.1080/10256017408623312
Popis: A method for free thyroxine estimation in serum, using labelled thyroxine and Sephadex G-25 has been developed. The experiment has been carried out by incubating labelled thyroxine with serum samples and separating the free thyroxine from bound protein in the serum by gel filtration after complete equilibrium between exogenous and endogenous thyroxine. Factors affecting the free thyroxine ratio such as volume of serum used, concentration of labelled thyroxine, time and temperature of incubation were studied and the optimum conditions for the test were selected. The sensitivity of the technique was determined by carrying out twelve estimations of the free thyroxine ratio on samples of pooled normal serum, pooled hypothyroid serum, and pooled hyperthyroid semm. In addition free thyroxine ratio leas determined for 23 hypothyroidisms, 99 euthyroid patients, 40 untreated thyrotoxicosis and 50 normal serum samples. A good correlation with the thyroid status of the patients (as determined) clinically and with ra...
Databáze: OpenAIRE