T4 RIA Kit

Name T4 RIA Test
Full name Human T4 RIA Test Kit
Category Name Thyroid RIA kits
Test 100
Principle Competitive RIA
Detection Range 0-320 ng/mL
Sample 25µL
Sensitivity 0.906 ng/mL
Total Time ~45 min
Shelf Life 45 Days from the manufacturing date

T4 RIA kit description:

The T4 RIA is intended for the quantitative determination of the Thyroxine (T4) concentration in human serum

Materials provided with T4 RIA Test Kit:

1. Coated Tubes: Thyroxine(T4)monoclonal antibody (100 tubes)

2. Thyroxine (T4) Antigen Labelled with I 125 (Tracer I125)

3. T4 standard set, contains 0, 20, 40, 80,160, 320,. ng/mL, ready for use

4. Control serum: T4 in serum with preservatives(1Vial, 1 ml)

Materials Required, not Provided:

1. Precision pipettes

2. Distilled or deionized water

3. Gama counter


Thyroxine (T4) or 3,5,3’,5’-tetraiodothyronine is the main thyroid gland hormone that is regulated by the hypothalamus and pituitary sensitive feedback mechanism. Secreted TRH by hypothalamus stimulates the pituitary to release TSH, which causes the release of T4 and T3 by affecting the thyroid. T3 and t4 hormones control the secretion of TSH and TRH by feedback mechanism. More than 99% of T4 is reversibly bound to three plasma proteins in blood - thyroxine binding globulin (TBG) binds 70%, thyroxine binding pre-albumin (TBPA) binds 20%, and albumin binds 10%; so, less than 0.1% of T4 is in the free, unbound state in blood at any time. This free T4 is able to enter to the cells and apply its biological effect by binding to TBG. Measurement of total T4 by immunoassay is the most reliable screening test for determination of the presence of thyroid disorders in patients. Increased levels of T4 have been found in hyper-thyroidism due to Grave’s disease and Plummer’s disease and in acute and subacute thyroiditis. Low levels of T4 have been associated with congenital hypothyroidism, myxedema, chronic thryoiditis (Hashimoto’s disease), and with some genetic abnormalities.

Principle of the assay

Immune radiometric assay (IRMA) kit, evaluates T4 based on the competitive reaction. The present T4 in the samples compete with Iodine-125 to attach to the coated rabbit anti polyclonal onto the end of the tube walls. After incubation period, the reaction mixture of the tube is discarded and then the radioactivity is measured in a gamma counter. The amount of activity form in the tube has an inverse relationship to the T4 concentration. T4 standards with known concentrations are tested with the unknown samples in which the concentration of unknown samples is achieved based on the standard curve of the counted amount against concentration of T4.