Description
Thyroglobulin (Tg), the precursor of thyroid hormones, is synthesised by thyrocytes and secreted into the lumen of thyroid follicles, where it is stored as the major component of colloid. At the cell-colloid interface, post-transitional modifications of Tg occur, which are characterised by coupling of tyrosyl residues within the Tg molecule with iodide, leading to the formation of thyroid hormone. Hormone release generally requires uptake of Tg from the colloid by thyrocytes and proteolytic cleavage along the lysosomal pathway. See Also Thyroxine (T4), Free Serum and Thyroid Stimulation Hormone
(TSH), Serum
Indications
Serum Tg concentration primarily reflects three factors: (a) the mass of differentiated thyroid tissue present; (b) any physical damage to or inflammation of the thyroid gland; and (c) the magnitude of TSH- receptor stimulation. Serum Tg measurement is used as a tumour marker for monitoring patients with differentiated thyroid carcinoma.
Sample Type, Quantity & Conditions
1 ml Serum 1 ml Li-Heparin or K2, K3-EDTA Plasma Stability: 48 Hours at 15-25 °C 72 Hours at 2-8 °C 1 Month at -20 °C
Special Precautions
Lipemic samples may interfere with the results.
Normal Range
3.5-77 ng/mL
