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Glutamine Colorimetric Assay Kit

based on 3 citations in multiple journalsGlutamine Colorimetric Assay Kit34.1 4
Catalog #: K556

Product Details

Cat # +Size K556-100
Size 100 assays
Detection Method Absorbance (450 nm)
Applications Measurement of Glutamine in various biological samples
Features & Benefits • Convenient & Rapid Protocol
• This kit can detect as little as 25 µM of Glutamine in a variety of biological samples
Kit Components • Hydrolysis Buffer
• Development Buffer
• Hydrolysis Enzyme Mix (Lyophilized)
• Development Enzyme Mix (Lyophilized)
• Developer (Lyophilized)
• Gln Standard (Lyophilized)
Storage Conditions -20°C
Shipping Conditions Gel Pack
USAGE For Research Use Only! Not For Use in Humans.


Glutamine (Gln) is one of the most abundant amino acids containing an uncharged amide as a side chain. It is synthesized via condensation of glutamate and ammonia. Gln is classified as a non-essential amino acid, however, Gln is important in several biological processes such as protein synthesis, regulation of acid-balance in mammalian kidneys and cell growth. It constitutes cell’s main source of nitrogen for the synthesis of nucleotides and hexosamines. Glutamine-rich diets benefit patients suffering from Crohn’s disease, severe burns, HIV/AIDS and cancer. BioVision’s Glutamine Colorimetric Assay kit is a simple and sensitive assay that detects the biologically relevant concentrations of Gln in various fluids and tissues. The assay is based on the hydrolysis of Glutamine to Glutamate producing a stable signal, which is directly proportional to the amount of Gln in the sample. The assay can detect as little as 25 µM of Gln in a variety of biological samples.

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Can this kit be used with samples like bacteria, plants, drosophila, yeast etc?
We have optimized the kit with mammalian samples. However, theoretically these kits should work with samples from multiple species/sources. Since the optimal conditions depend on the sample type, the protocol has to be be adapted to fit the samples for efficient results. Please refer to this kit's citations to see what kind of samples have been used with this kit other than mammalian samples.
Can we use frozen samples with this assay?
Fresh samples are always preferred over frozen samples. However, frozen samples can also be used, provided, they were frozen right after isolation, were not freeze thawed multiple time (for which we recommend aliquoting the samples before freezing) and have been frozen for relatively short periods.
Can we use a different wavelength than recommended for the final analysis?
It is always recommended to use the exact recommended wavelength for the most efficient results. However, most plate readers have flexibility in their band width of detection in increments of +/- 10 nm. Depending on this flexibility range, you can deviate from the recommended wavelengths within limits.
What is the exact volume of sample required for this assay?
There is no specific volume we can recommend for the amount any sample to be used since it is completely sample concentration and quality based. You have to do a pilot expt with multiple sample volumes to determine the optimal volume which gives a reading within the linear range of the standard curve. Please refer to the citations for this product to see what other clients have used with similar sample types.
Do you have trial sizes of this kit?
Unfortunately, we do not have trial sizes of this kit available. However, if you are based in the US or Canada, we will give you a 10% off list price introductory discount on its purchase price. If you are based out of this area please contact yopur regional BioVision distributor.
What is the shelf life of this kit?
This kit is good for 12 months from the date of shipment in the unopened form when stored at the appropriate temperature and appropriate conditions. After opening and reconstitution, some of the components in this kit are good for 2 months at -20°C. Please refer to the datasheet for storage information and shelf life of each of the components.
Why are my standard curve values lower than those shown on the datasheet?
There are multiple factors which influence the signals like the incubation times, room temperature, handling etc. In general, to increase the value of the standards, you can increase the incubation time. As long as the standard curve is linear, it should be fine to use, since all of your samples will also be measured under the same conditions on this curve.
How do I normalize my samples against protein concentration
You can use a protein quantitation assay on the supernatants you get from cell/tissue lysates or with any other liquid sample in the assay buffer.
Can we purchase individual components of this kit?
Yes, you can purchase any of the kit's components without the whole kit. Please refer to the component Cat #s mentioned on the datasheet for ordering.
Can we use an alternate buffer for sample preparation (cell lysis, sample dilutions etc)?
Our assay buffers are optimized for the reactions they are designed for. They not only contain some detergents for efficient lysis of your cells/tissue, but also contain some proprietary components required for the further reactions. Therefore, we highly recommend using the buffers provided in the kit for the best results.
Should I make a standard curve for every expt I do, or is one curve/kit enough?
Yes, I would strongly recommend you to do the standards every time you do the expt. There is always a chance that something was done differently that day and we do not want any conditions to differ between standards and samples.
Can pyroglutamate, a product from the glutamine deamination, be detected by using this Kit?
Pyroglutamate is not a known substrate for the enzyme involved in the conversion mechanism-hence should not be detected by this kit.
What should be an optimal pH of the samples?
The key enzyme involved in the kit is active at acidic pH and gets deactivated at neutral pH, i.e.pH> 7.4. The assay is geared towards typical tissue lysates and cell lysates that are homogenized in the hydrolysis buffer which has an acidic pH and keeps the enzyme happy. Biological samples like plasma/serum tend to have a very high concentration of Glutamine, so we can use very little volume- such low volumes don’t affect the pH as much.
What types of compounds (outside of glutamate) might interfere with the reaction?
Apart from glutamate, NADH in the sample can also cause color formation. Run background control without the hydrolysis enzyme mix and subtract this value from the sample reaction with the hydrolysis reaction.
Does this kit contain any recombinant proteins? If yes, would you tell us the expression system of the protein?
K556-100-3 contains recombinant protein from E.ColiK556-100-4 contains protein from bovine liver.
What is a good protocol to prepare the cell homogenate so that these metabolites are preserved for the assays?
Here is a protocol: - The adherent cells can be removed from attachment by trypsinization.- Spin down cells and aspirate trypsin+ media - Add respective assay buffer to the cells- Homogenize using a dounce homogenizer: Spin down and take the supernatant for the assayWe recommend optimizing the sample volume for each assay in a small scale pilot experiment with one or two samples to make sure the values obtained are in the linear range of the std. curve.
Leandro R. Soria, Hepatic glutamine synthetase augmentation enhances ammonia detoxification., J Inherit Metab Dis, Nov. 2019, 30724386
Mokgadi Violet Gwangwa, Effects of glutamine deprivation on oxidative stress and cell survival in breast cell lines. Biol Res, Mar 2019; 30917872.
Mus, F. et al., (2017) Diazotrophy overcomes the deleterious growth phenotype of glnE deletion in Azotobacter vinelandii, Appl. Environ. Microbiol, Oct.2017, online
Mus F et al., (2017) Diazotrophy overcomes the deleterious growth phenotype of glnE deletion in Azotobacter vinelandii, Appl. Environ. Microbiol., 2017, April 21: epub
Lim et al., Targeting Mitochondrial Oxidative Metabolism in Melanoma Causes Metabolic Compensation through Glucose and Glutamine Utilization. Cancer Res., Jul 2014; 74: 3535 - 3545.
For more citations of this product click here