Method for the measurement of free thyroxine or 3,5,3'- triiodothyronine in a liquid sample

摘要

An immunoassay for the measurement of free thyroid hormone, i. e., thyroxine or 3,5,3'-triiodothyronine, in a liquid sample in which the thyroid hormone is present in both free and combined states, which immunoassay comprises the steps of:PPA. combining the sample with a labeled thyroid hormone-horseradish peroxidase conjugate which does not significantly interact with the thyroxine-binding globulin and thyroxine-binding prealbumin originally present in the sample and immobilized antibody which is specific for the thyroid hormone;P PB. incubating the resulting mixture;PPC. separating a solid phase from the liquid phase; andPPD. measuring the amount of labeled thyroid hormone-horseradish peroxidase conjugate present in either phase by means of the activity of the label.