| sST2

ST2 is a member of the interleukin 1 receptor family. The ST2 protein has two isoforms and is directly implicated in the progression of cardiac disease: a soluble form (referred to as soluble ST2 or sST2) and a membrane-bound receptor form (referred to as the ST2 receptor or ST2L). When the myocardium is stretched, the ST2 gene is upregulated, increasing the concentration of circulating soluble ST2.[3] The ligand for ST2 is the cytokine interleukin-33 (IL-33). Binding of IL-33 to the ST2 receptor, in response to cardiac disease or injury, such as an ischemic event, elicits a cardioprotective effect resulting in preserved cardiac function. This cardioprotective IL-33 signal is counterbalanced by the level of soluble ST2, which binds IL-33 and makes it unavailable to the ST2 receptor for cardioprotective signaling. As a result, the heart is subjected to greater stress in the presence of high levels of soluble ST2.
 

| 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)	2000	1000	500	250	125	62.5	31.25	0
OD	2.70	1.78	1.12	0.64	0.37	0.20	0.10	0.03
Corrected OD	2.67	1.75	1.09	0.61	0.34	0.17	0.07	-

 

| Repeatability

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

| Recovery

The recovery of Mouse sST2 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)	82-114	98
Plasma(n=8)	84-108	96
Cell Culture Supernates(n=8)	83-110	94

 

| Linearity

Samples were spiked with high concentrations of Mouse sST2 and diluted with Universal Diluent to produce samples with values within the range of the assay.

 

		Serum(n=4)	Plasma(n=4)	Cell Culture Supernates(n=4)
1 : 2	Range (%)	92-113	87-113	86-106
	Average (%)	102	101	98
1 : 4	Range (%)	84-105	88-112	83-114
	Average (%)	93	100	104