4018 – Medizym® Tg Rem
The Medizym® Tg Rem is a quantitative immunoassay for the determination of Thyroglobulin (Tg) in human serum. The Medizym® Tg Rem is intended as an aid in the diagnosis of thyroid disorders in conjunction with other clinical and laboratory findings.
Thyroglobulin (Tg), an iodine containing glycoprotein and precursor of the thyroid hormones thyroxine (T4) and triiodothyronine (T3), is a major component of thyroid colloid. The biosynthesis of Tg is regulated by thyrotropin, the only thyroid tissue that can produce, store and secrete Tg; Tg is thus organ- and tissue specific; this specificity is the main indication of the Tg determination in monitoring differentiated thyroid carcinoma, essential in the early detection and exclusion of metastases or tumour relapses. This indication is also used in the follow-up of radioiodine treatments. Serum Tg measurements plays a major diagnostic role in the management of patients with differentiated thyroid carcinoma (DTC) after treatment; measurable and increasing serum Tg levels are an early and reliable indicator of persistent or recurrent disease. Additionally, serum Tg measurements can be useful in the diagnosis of neonatal hypothyroidism. In hyperthyroid adults undetectable serum Tg suggests thyrotoxicosis factitia. Other indications of increased serum Tg levels are found in various non-malignant thyroid diseases, e.g. Hashimoto`s thyroiditis, Graves` disease, and non-toxic diffuse goiter, although in these cases, the actual Tg levels do not relate to disease severity in these conditions.
The Medizym* Tg Rem is an immunoenzymometric assay (IEMA). One of the two specially selected monoclonal anti-Tg antibodies is immobilized onto the surface of microtiter plates. The other one is horseradish peroxidase (HRP) labeled and acts as conjugate. Both monoclonals are used in excess and bind Tg at different epitopes, which are relatively free from interferences.
Tg of serum samples, controls and calibrators react with the solid phase bound anti-hTg antibody during the first incubation period of 2.5 hours at room temperature. After removal of the non-bound components by a washing step anti-hTg HRP conjugate interacts with the Tg molecules trapped by the immobilized anti-hTg antibody during the second incubation at room temperature over night (> 15 hours). The sandwich type complexes formed are separated from unbound material by a further washing step. HRP converts the colorless substrate solution of 3,3’,5,5’-tetramethylbenzidine (TMB) added into a blue product. The enzyme reaction is stopped by dispensing an acidic solution (H2SO4) into the wells after 15 min, turning the solution from blue to yellow.
The signal intensity of the reaction product is proportional to the antigen activity in the sample. After stopping the signal intensity of the reaction product is measured photometrically.
The immunoassay is designed for manual professional in vitro diagnostic use.
|Title||Medizym® Tg Rem|
|Description||Enzyme immunoassay for the quantitative determination of Thyroglobulin (Tg) in human serum|
|Format||Microtiter plate coated with antibodies to thyroglobulin (mouse, monoclonal)|
|Total incubation time||Overnight + 165 min.|
|Sample volume||25 µL serum|
|No. of determinations||96 (86 x 1) 8 x Calibrators and 2 x Controls|