title: Semi-automated radioimmunoassays for total serum thyroxine and triiodothyronine.
abstract: Single stage semi-automated radioimmunoassays for total serum thyroxine (T4) and triiodothyronine (T3) are described which employ an automatic pipetting station, automatic gamma counter, and a programmable calculator with paper tape reader and printing facility. Both assays require only a small volume of unextracted serum, and are specific and sensitive. Their sample capacity, precision, speed, and cost are comparable with the measurement of serum protein-bound iodine. Both assays therefore have significant advantages over previous methods for the assessment of thyroid function in the diagnostic laboratory. A Simple method of automating the calculation of results is described, which is applicable to any radioimmunoassay in which the standard curve is approximately linear on a plot of the free/bound fraction against the antigen concentration. In addition, a general method is reported which reveals the relative contributions of intrinsic, systematic, and random error to radioimmunoassay precision.
mesh_terms: D000704:Analysis of Variance; D001322:Autoanalysis; D003365:Costs and Cost Analysis; D005069:Evaluation Studies as Topic; D006801:Humans; D008722:Methods; D011863:Radioimmunoassay; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*
chemical_list: D014284:Triiodothyronine; D013974:Thyroxine