| ENK

An enkephalin is a pentapeptide involved in regulating nociception (pain sensation) in the body. The enkephalins are termed endogenous ligands, as they are internally derived (and therefore endogenous) and bind as ligands to the body's opioid receptors. Discovered in 1975, two forms of enkephalin have been found, one containing leucine, and the other containing methionine. Both are products of the proenkephalin gene.Enkephalin is also considered a neuropeptide, which in the human body performs as an important signaling molecule in the brain. Enkephalins are found in high concentration in the brain as well as in the cells of adrenal medulla. In response to pain, norepinephrine, a hormone that is activated in fight-or-flight response, is released along with endorphins.
 

| 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 (pg/mL)	800	400	200	100	50	25	12.5	0
OD	0.188	0.27	0.389	0.642	0.929	1.38	1.766	1.842

 

| Repeatability

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

| Recovery

The recovery of Human ENK 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)	81-101	95
Plasma(n=8)	92-105	101

 

| Linearity

Samples were spiked with high concentrations of Human ENK 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 (%)	83-95	88-96
	Average (%)	91	93
1 : 4	Range (%)	89-104	87-108
	Average (%)	93	98