| T4

Thyroxine (T4) is produced and secreted by the thyroid gland. Each molecule of T4 consists of protein and iodine (in the form of iodide). It contains four molecules of iodide, hence the name T4. The primary form of thyroid hormone in the blood is T4, which has a longer half-life than T4. Within cells, it is converted by deiodinase (5′-deiodinase) into active T4 (three to four times more potent than T4). These substances undergo further processing through decarboxylation and deiodination, yielding iodothyronine (T1a) and thyronine (T0a).
 

| Typical data

As the OD values of the standard curve may vary according to the conditions of the actual assay performance (e.g. operator, pipetting technique, wash technique or temperature effects), the operator should establish a standard curve for each test. Typical standard curve and data are provided below for reference only.

 

Concentration (ng/mL)	10	5	2.5	1.25	0.625	0.312	0.156	0
OD	0.216	0.298	0.417	0.669	0.955	1.405	1.79	1.865

 

| Repeatability

Intra-assay Precision (Precision within an assay)：CV% < 10%; Inter-assay Precision (Precision between assays)：CV% < 10%
 

| Recovery

The recovery of T4 spiked at three different levels in samples throughout the range of the assay was evaluated in various matrices.

 

Sample Type	Range(%)	Average Recovery(%)
Serum(n=8)	88-102	97
Plasma(n=8)	93-107	104

 

| Linearity

Samples were spiked with high concentrations of T4 and diluted with Universal Diluent to produce samples with values within the range of the assay.

 

		Serum(n=4)	Plasma(n=4)
1 : 2	Range (%)	82-96	88-97
	Average (%)	91	93
1 : 4	Range (%)	89-103	87-110
	Average (%)	94	98