| ISG15

Interferon-stimulated gene 15 (ISG15) is a 17 kDa secreted protein that in humans is encoded by the ISG15 gene. ISG15 is induced by type I interferon (IFN) and serves many functions, acting both as an extracellular cytokine and an intracellular protein modifier. The precise functions are diverse and vary among species but include potentiation of Interferon gamma (IFN-II) production in lymphocytes, ubiquitin-like conjugation to newly-synthesized proteins and negative regulation of the IFN-I response.
 

| 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)	50	25	12.5	6.25	3.12	1.56	0.78	0
OD	2.56	1.45	0.8	0.48	0.33	0.23	0.2	0.08
Corrected OD	2.48	1.37	0.72	0.4	0.25	0.15	0.12	-

 

| Repeatability

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

| Recovery

The recovery of Human ISG15 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)	84-101	96
Plasma(n=8)	92-105	102
Cell Culture Supernates(n=8)	96-108	105

 

| Linearity

Samples were spiked with high concentrations of Human ISG15 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 (%)	84-96	88-96	90-110
	Average (%)	91	93	96
1 : 4	Range (%)	89-103	87-108	105-115
	Average (%)	94	98	108