Human Total T4 (Thyroxine) ELISA Kit

Sample

serum

Species Reactivity

Human

Detection Method

cELISA

Intended Use

For the quantitative determination of the Total Thyroxine (T4) concentration in human serum

Contents of Kit

1. Antibody-Coated Wells: Microtiter wells coated with sheep anti-T4. 96 wells
2. Enzyme Conjugate Concentrate 11×: Contains T4-HRP Conjugate 1.3 mL
3. Enzyme Conjugate Diluent: Contains ANS, TRIS buffer, pH=7.60 and ProClin-300. 13 mL
4. Reference Standard Set (1 mL/vial): Contains 0, 2.0, 5.0, 10.0, 15.0 and 25.0 μg/dL in T3/T4-free stripped human serum, 1 set, liquid, ready-to-use. 1 mL / vial
5. TMB Reagent (One-Step): Contains 3, 3', 5, 5' tetramethylbenzidine (TMB) stabilized in buffer solution. 11 mL
6. Stop Solution (1N HCl): Contains diluted hydrochloric acid. 11 mL

Storage

1. Store the unopened kit at 2°C to 8°C upon receipt and when not in use, until the expiration shown on the kit label. Refer to the package label for the expiration date.
2. The opened and used reagents are stable until the expiration date if stored properly at 2-8°C.
3. Keep microtiter plate in a sealed bag with desiccant to minimize exposure to damp air.

Precision

Intra-Assay Precision
Within-run precision was determined by replicate determinations of three different control sera in 1 assay.

Inter-Assay Precision
Between-run precision was determined by replicate measurements of three different serum samples in several different assays.

Sensitivity

The analytical sensitivity of the method is defined as the lowest concentration of T4 that can be distinguished from 0 μg/dL as calculated from the 95% confidence limits of the 0 μg/dL standard absorbance. The analytical sensitivity of the assay is 0.5 μg/dL

General Description

The thyroid hormones thyroxine (T4) and triiodothyronine (T3), are synthesized and stored in the thyroid gland and circulate in the bloodstream mostly bound to the plasma protein, thyroxine binding globulin (TBG).¹ The thyroid gland and associated hormones are a major component of the endocrine system. They exert powerful and essential regulatory influences on growth, differentiation, cellular metabolism, and general hormonal balance of the body. Proteolytic cleavage of follicular thyroglobulin releases T4 into the bloodstream. Greater 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%.^2,3 Approximately 0.03% of T4 is in the free, unbound state in blood at any one time. Diseases affecting thyroid function may present a wide array of confusing symptoms1 . Measurement of total T4, TSH, Free T3 and Free T4 by immunoassay are reliable and convenient methods to determine the presence of thyroid disorders in patients.^4,5 Increased levels of T4 have been found in hyperthyroidism 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.

Standard Curve

Example of standard curve
Results of a typical standard run with optical density readings at 450 nm shown on the Y-axis against Total T4 concentrations (μg/dL) shown on the X-axis, are presented below. NOTE: the standard curve is for illustration only, and should not be used to calculate unknowns. Each laboratory must provide its own data and standard curve for each assay run. Additionally, the absorbance (450 nm) values can be varied due to incubation at different room temperature in different laboratories.