| GS

Glutamine synthetase (GS) is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate. Glutamine synthetase uses ammonia produced by nitrate reduction, amino acid degradation, and photorespiration. The amide group of glutamate is a nitrogen source for the synthesis of glutamine pathway metabolites. GS is present predominantly in the brain, kidneys, and liver. GS in the brain participates in the metabolic regulation of glutamate, the detoxification of brain ammonia, the assimilation of ammonia, recyclization of neurotransmitters, and termination of neurotransmitter signals.
 

| 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)	1000	500	250	125	62.5	31.25	15.62	0
OD	2.03	1.21	0.69	0.41	0.29	0.23	0.19	0.09
Corrected OD	1.94	1.12	0.6	0.32	0.2	0.14	0.1	-

 

| Repeatability

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

| Recovery

The recovery of Human GS 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
Tissue Homogenates(n=8)	96-108	104

 

| Linearity

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

 

		Serum(n=4)	Plasma(n=4)	Tissue Homogenates(n=4)
1 : 2	Range (%)	83-95	88-96	90-110
	Average (%)	90	93	96
1 : 4	Range (%)	89-103	87-108	105-116
	Average (%)	94	98	108