Human Glutamine synthetase (GLUL) ELISA Kit

Product Name:	Human Glutamine synthetase (GLUL) ELISA Kit
SKU:	HUEB0445
Size:	96T
Target:	Human Glutamine synthetase (GLUL)
Synonyms:	Glutamate--ammonia ligase, Palmitoyltransferase GLUL, GS, GLNS
Assay Type:	Sandwich
Detection Method:	ELISA
Reactivity:	Human
Detection Range:	15.6-1000pg/mL
Sensitivity:	9.1pg/mL

Intra CV:

4.8%

Inter CV:

7.7%

Linearity:

Sample	1:2	1:4	1:8	1:16
Serum(N=5)	103-113%	90-100%	88-98%	90-100%
EDTA Plasma(N=5)	109-117%	101-111%	96-106%	100-110%
Heparin Plasma(N=5)	103-115%	102-114%	87-99%	97-108%

Recovery:

Sample Type	Average(%)	Recovery Range(%)
Serum	95	89-101
Plasma	97	91-103

Function:

Glutamine synthetase that catalyzes the ATP-dependent conversion of glutamate and ammonia to glutamine (PubMed:30158707, PubMed:16267323). Its role depends on tissue localization: in the brain, it regulates the levels of toxic ammonia and converts neurotoxic glutamate to harmless glutamine, whereas in the liver, it is one of the enzymes responsible for the removal of ammonia (By similarity). Essential for proliferation of fetal skin fibroblasts (PubMed:18662667). Independently of its glutamine synthetase activity, required for endothelial cell migration during vascular development: acts by regulating membrane localization and activation of the GTPase RHOJ, possibly by promoting RHOJ palmitoylation (PubMed:30158707). May act as a palmitoyltransferase for RHOJ: able to autopalmitoylate and then transfer the palmitoyl group to RHOJ (PubMed:30158707). Plays a role in ribosomal 40S subunit biogenesis (PubMed:26711351).

Uniprot:	P15104
Sample Type:	Serum, plasma, tissue homogenates, cell culture supernates and other biological fluids
Specificity:	Natural and recombinant human Glutamine synthetase
Sub Unit:	Decamer; composed of two pentamers (PubMed:18005987). Interacts with PALMD (By similarity). Interacts with RHOJ (PubMed:30158707).
Research Area:	Neurosciences
Subcellular Location:	Cytoplasm Cytosol Microsome Mitochondrion Cell membrane Lipid-anchor Mainly localizes in the cytosol, with a fraction associated with the cell membrane.
Storage:	Please see kit components below for exact storage details
Note:	For research use only

UniProt Protein Function:	GLUL: This enzyme has 2 functions: it catalyzes the production of glutamine and 4-aminobutanoate (gamma-aminobutyric acid, GABA), the latter in a pyridoxal phosphate-independent manner. Essential for proliferation of fetal skin fibroblasts. Defects in GLUL are the cause of congenital systemic glutamine deficiency (CSGD). CSGD is a rare developmental disorder with severe brain malformation resulting in multi-organ failure and neonatal death. Glutamine is largely absent from affected patients serum, urine and cerebrospinal fluid. Belongs to the glutamine synthetase family.
UniProt Protein Details:	Protein type:Amino Acid Metabolism - alanine, aspartate and glutamate; Amino Acid Metabolism - arginine and proline; EC 6.3.1.2; Energy Metabolism - nitrogen; EC 4.1.1.15; Ligase Chromosomal Location of Human Ortholog: 1q31 Cellular Component: cytoplasm; cytosol; nucleus Molecular Function:glutamate-ammonia ligase activity; identical protein binding; protein binding Biological Process: amino acid biosynthetic process; cell proliferation; glutamate catabolic process; glutamine biosynthetic process; neurotransmitter uptake Disease: Glutamine Deficiency, Congenital
NCBI Summary:	The protein encoded by this gene belongs to the glutamine synthetase family. It catalyzes the synthesis of glutamine from glutamate and ammonia in an ATP-dependent reaction. This protein plays a role in ammonia and glutamate detoxification, acid-base homeostasis, cell signaling, and cell proliferation. Glutamine is an abundant amino acid, and is important to the biosynthesis of several amino acids, pyrimidines, and purines. Mutations in this gene are associated with congenital glutamine deficiency, and overexpression of this gene was observed in some primary liver cancer samples. There are six pseudogenes of this gene found on chromosomes 2, 5, 9, 11, and 12. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2014]
UniProt Code:	P15104
NCBI GenInfo Identifier:	1169929
NCBI Gene ID:	2752
NCBI Accession:	P15104.4
UniProt Secondary Accession:	P15104,Q499Y9, Q5T9Z1, Q7Z3W4, Q8IZ17,
UniProt Related Accession:	P15104
Molecular Weight:	42,064 Da
NCBI Full Name:	Glutamine synthetase
NCBI Synonym Full Names:	glutamate-ammonia ligase
NCBI Official Symbol:	GLUL
NCBI Official Synonym Symbols:	GS; GLNS; PIG43; PIG59
NCBI Protein Information:	glutamine synthetase
UniProt Protein Name:	Glutamine synthetase
UniProt Synonym Protein Names:	Glutamate decarboxylase (EC:4.1.1.15); Glutamate--ammonia ligase
UniProt Gene Name:	GLUL
UniProt Entry Name:	GLNA_HUMAN

Component	Quantity (96 Assays)	Storage
ELISA Microplate (Dismountable)	8×12 strips	-20°C
Lyophilized Standard	2	-20°C
Sample Diluent	20ml	-20°C
Assay Diluent A	10mL	-20°C
Assay Diluent B	10mL	-20°C
Detection Reagent A	120µL	-20°C
Detection Reagent B	120µL	-20°C
Wash Buffer	30mL	4°C
Substrate	10mL	4°C
Stop Solution	10mL	4°C
Plate Sealer	5	-

Other materials and equipment required:

Microplate reader with 450 nm wavelength filter
Multichannel Pipette, Pipette, microcentrifuge tubes and disposable pipette tips
Incubator
Deionized or distilled water
Absorbent paper
Buffer resevoir

*Note: The below protocol is a sample protocol. Protocols are specific to each batch/lot. For the correct instructions please follow the protocol included in your kit.

Allow all reagents to reach room temperature (Please do not dissolve the reagents at 37°C directly). All the reagents should be mixed thoroughly by gently swirling before pipetting. Avoid foaming. Keep appropriate numbers of strips for 1 experiment and remove extra strips from microtiter plate. Removed strips should be resealed and stored at -20°C until the kits expiry date. Prepare all reagents, working standards and samples as directed in the previous sections. Please predict the concentration before assaying. If values for these are not within the range of the standard curve, users must determine the optimal sample dilutions for their experiments. We recommend running all samples in duplicate.

Step
1.	Add Sample: Add 100µL of Standard, Blank, or Sample per well. The blank well is added with Sample diluent. Solutions are added to the bottom of micro ELISA plate well, avoid inside wall touching and foaming as possible. Mix it gently. Cover the plate with sealer we provided. Incubate for 120 minutes at 37°C.
2.	Remove the liquid from each well, don't wash. Add 100µL of Detection Reagent A working solution to each well. Cover with the Plate sealer. Gently tap the plate to ensure thorough mixing. Incubate for 1 hour at 37°C. Note: if Detection Reagent A appears cloudy warm to room temperature until solution is uniform.
3.	Aspirate each well and wash, repeating the process three times. Wash by filling each well with Wash Buffer (approximately 400µL) (a squirt bottle, multi-channel pipette,manifold dispenser or automated washer are needed). Complete removal of liquid at each step is essential. After the last wash, completely remove remaining Wash Buffer by aspirating or decanting. Invert the plate and pat it against thick clean absorbent paper.
4.	Add 100µL of Detection Reagent B working solution to each well. Cover with the Plate sealer. Incubate for 60 minutes at 37°C.
5.	Repeat the wash process for five times as conducted in step 3.
6.	Add 90µL of Substrate Solution to each well. Cover with a new Plate sealer and incubate for 10-20 minutes at 37°C. Protect the plate from light. The reaction time can be shortened or extended according to the actual color change, but this should not exceed more than 30 minutes. When apparent gradient appears in standard wells, user should terminatethe reaction.
7.	Add 50µL of Stop Solution to each well. If color change does not appear uniform, gently tap the plate to ensure thorough mixing.
8.	Determine the optical density (OD value) of each well at once, using a micro-plate reader set to 450 nm. User should open the micro-plate reader in advance, preheat the instrument, and set the testing parameters.
9.	After experiment, store all reagents according to the specified storage temperature respectively until their expiry.

When carrying out an ELISA assay it is important to prepare your samples in order to achieve the best possible results. Below we have a list of procedures for the preparation of samples for different sample types.

Sample Type	Protocol
Serum	If using serum separator tubes, allow samples to clot for 30 minutes at room temperature. Centrifuge for 10 minutes at 1,000x g. Collect the serum fraction and assay promptly or aliquot and store the samples at -80°C. Avoid multiple freeze-thaw cycles. If serum separator tubes are not being used, allow samples to clot overnight at 2-8°C. Centrifuge for 10 minutes at 1,000x g. Remove serum and assay promptly or aliquot and store the samples at -80°C. Avoid multiple freeze-thaw cycles.
Plasma	Collect plasma using EDTA or heparin as an anticoagulant. Centrifuge samples at 4°C for 15 mins at 1000 × g within 30 mins of collection. Collect the plasma fraction and assay promptly or aliquot and store the samples at -80°C. Avoid multiple freeze-thaw cycles. Note: Over haemolysed samples are not suitable for use with this kit.
Urine & Cerebrospinal Fluid	Collect the urine (mid-stream) in a sterile container, centrifuge for 20 mins at 2000-3000 rpm. Remove supernatant and assay immediately. If any precipitation is detected, repeat the centrifugation step. A similar protocol can be used for cerebrospinal fluid.
Cell culture supernatant	Collect the cell culture media by pipette, followed by centrifugation at 4°C for 20 mins at 1500 rpm. Collect the clear supernatant and assay immediately.
Cell lysates	Solubilize cells in lysis buffer and allow to sit on ice for 30 minutes. Centrifuge tubes at 14,000 x g for 5 minutes to remove insoluble material. Aliquot the supernatant into a new tube and discard the remaining whole cell extract. Quantify total protein concentration using a total protein assay. Assay immediately or aliquot and store at ≤ -20 °C.
Tissue homogenates	The preparation of tissue homogenates will vary depending upon tissue type. Rinse tissue with 1X PBS to remove excess blood & homogenize in 20ml of 1X PBS (including protease inhibitors) and store overnight at ≤ -20°C. Two freeze-thaw cycles are required to break the cell membranes. To further disrupt the cell membranes you can sonicate the samples. Centrifuge homogenates for 5 mins at 5000xg. Remove the supernatant and assay immediately or aliquot and store at -20°C or -80°C.
Tissue lysates	Rinse tissue with PBS, cut into 1-2 mm pieces, and homogenize with a tissue homogenizer in PBS. Add an equal volume of RIPA buffer containing protease inhibitors and lyse tissues at room temperature for 30 minutes with gentle agitation. Centrifuge to remove debris. Quantify total protein concentration using a total protein assay. Assay immediately or aliquot and store at ≤ -20 °C.
Breast Milk	Collect milk samples and centrifuge at 10,000 x g for 60 min at 4°C. Aliquot the supernatant and assay. For long term use, store samples at -80°C. Minimize freeze/thaw cycles.

ELISA	Antibodies
Human GLN1 / Glutamine Synthetase ELISA Kit	Anti-Glutamine Synthetase Antibody (CAB19641)
Mouse GS (Gelsolin) CLIA Kit (MOES00287)	Anti-GLUL Antibody (CAB5437)[KO Validated]
	GLUL Antibody (PACO01754)
	GLUD2 Antibody (PACO09492)
	PPAT Antibody (PACO16423)