Radioimmunoassay for human thyroglobulin

Human thyroglobulin was isolated from thyroid tissue taken from thyrotoxic patients undergoing surgical thyroidectomy. After thyroglobulin fractionation on Sephadex G-200 and Sepharose 4B columns highly purified thyroglobulin preparation was obtained which was appropriate for immunization of laboratory animals and labelling with 125-iodine. This made it possible to introduce a sensitive radioimmunoassay for serum thyroglobulin. In healthy subjects serum thyroglobulin concentration ranged between 1 and 34 ng/ml. In patients with thyrotoxicosis serum thyroglobulin was elevated, the values been from 40 to above 1000 ng/ml. In all patients the administration of TSH was followed by a marked rise in serum thyroglobulin, the values were at least 5 times higher than under the basal condition. (author)