Automated measurement of serum thyroxine with the "ARIA II," as compared with competitive protein binding and radioimmunoassay.

Positive interference in Radioimmunoassay determination of serum total T3

Introduction: Determination of thyrotropin, total and free thyroxine and triiodothyronine are widely used as diagnostic methods for thyroid function evaluation. There have been numerous reports of interferences in thyroid hormone immunoassays. Herein, a prominent positive interference is reported for a radioimmunoassay kit of total triiodothyronine. Materials and Methods: In this study, a total...

Performance characteristics of three automated immunoassays for thyroid hormones

Background: Since the introduction of the first radioimmunoassay, several improvements have been made in the design of immunoassays such as method of antibody production, labeling, automation and detection technology. We performed an analytical evaluation of the new electrochemiluminescent immunoassay (ECLIA) for serum TSH, FT4 and T3 in the Elecsys 2010 immunoassay system and compared the resu...

Evaluation of assays for thyroxine, triodotyronine and thyroid-stimulating hormone on the ARIA II automated radioimmunoassay instrument

A comparative study of serum total thyroxine estimation on unextracted serum by radioimmunoassay and by competitive protein binding.

A rapid and precise radioimmunoassay (RIA) for serum total thyroxine (T4) on as little as 1-10 mul of unextracted serum is described. Results in hypothyroidism (overt and borderline), in euthyroid subjects in pregnant and oestrogen-medicated subjects, and in hyperthyroidism (overt and borderline) are compared with the results on the same sera by an established competitive protein binding techni...

Radioimmunoassay of thyroxine in unextracted serum, by a single-antibody technique.

A radioimmunoassay procedure for thyroxine (14) is described, for which only 25 il of serum is required. The antibody, commercially available, is produced in rabbits in response to injections of a T4-albumin conjugate. Native T4-binding proteins are denatured by heating 25 .tl of serum in 0.2 ml of a glutamate buffer in a boiling water bath. After a 1-h incubation of heat-treated serum with l12...