Call 408.493.1800 | Fax 408.493.1801 | Toll Free 800.891.9699 (US Only) | Email: [email protected]

GST Colorimetric Activity Assay Kit

based on 4 citations in multiple journalsGST Colorimetric Activity Assay Kit44.1 4
Catalog #: K263

Product Details

Cat # +Size K263-100
Size 100 assays
Detection Method Absorbance (380 nm)
Species Reactivity Mammalian
Applications The kit can detect GST activity in crude cell lysate or purified protein fraction, and also quantitate GST-tagged fusion protein.
Features & Benefits • Simple procedure; takes only ~1-1.5 hours
• Fast and convenient
Kit Components • GST Assay Buffer
• GST Substrate (CDNB)
• Glutathione (GSH, lyophilized)
• GST Positive Control (0.625 µg/µl)
Storage Conditions -20°C
Shipping Conditions Gel Pack
USAGE For Research Use Only! Not For Use in Humans.


Glutathione S-transferase (GST) is a family of enzymes that play an important role in detoxification of xenobiotics. GST catalyzes the formation of the thiol group of glutathione to electrophilic xenobiotics. It utilizes glutathione to scavenge potentially toxic compounds including those produced as a result of oxidative stress and is part of the defense mechanism against the mutagenic, carcinogenic and toxic effects of such compounds. The GST Colorimetric Activity Assay Kit is based upon the GST-catalyzed reaction between GSH and the GST substrate, CDNB (1-chloro-2,4-dinitrobenzene, which has the broadest range of isozyme detectability (e.g., alpha-, mu-, pi-, and other GST isoforms). Under certain conditions, the interaction between glutathione and CDNB is totally dependent on the presence of active GST. The GST-catalyzed formation of GS-DNB produces a dinitrophenyl thioether which can be detected by spectrophotometer at 340 nm. One unit of GST activity is defined as the amount of enzyme producing 1 µmol of GS-DNB conjugate/min under the conditions of the assay. The kit can detect GST activity in crude cell lysate or purified protein fraction, and also quantitate GST-tagged fusion protein. Detect limit: Active GST < 4 mU.

Why buy BioVision Products?
Global Presence
Technical Support
BioVision aims to provide our customers innovative tools for accelerating drug discovery and biological research. BioVision offers >8,000 products including the most comprehensive array of assay kits for key targets in Metabolic pathways.
BioVision is committed to providing the highest quality products at a competitive price.
We have a broad network of global distributors who are ready to address your research needs and ensure fast delivery.
Our highly trained Technical Support team provides comprehensive product support and is dedicated to resolving your issues quickly and efficiently.
We want to measure GST activity in lung pipe, but cannot decide between products #K260-100, GST Fluorometric Activity Assay Kit and #K263-100  GST Colorimetric Activity Assay Kit. We want to make sure the sensitivity of each one?
Fluorometric assays in general are more sensitive than the colorimetric assays. In this particlar case, the detection sensitivity of K260-100 is < 0.5 mU, whereas the K263 is < 4 mU. But the fluorimetric detection requires filters for Ex/Em = 380/460 nm and the colorimetric detection requires 380 nm. Based on the availability of these filters and the antivipated GST levels, you can choose between K260 and K263.
What is the difference between K260 and K263 kits?
There are some fundamental differences between these 2 kits, although both measure GST activity. A few of these differences which might make your decision of making a choice easier are:
Flurometric assay requiring filters for Ex/Em: 380/461 nm
Detection limit: < 0.5 mU
Based on sample GST catalyzing a reaction between the provided MCB substrate and Glutathione.

Colorimetric assay requiring filter for 380 nm
Detection limit: < 4 mU Based on the GST-catalyzed reaction between GSH and the GST substrate, CDNB.
Can this kit be used with samples like bacteria, plants, drosophila 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 -20C. 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.
Samir Ali Abd El-Kaream. Biochemical and biophysical study of chemopreventive and chemotherapeutic anti-tumor potential of some Egyptian plant extracts. Biochem Biophys Rep. Apr 2019. 31016248
Li et al., Glutathione-Mediated Detoxification of Halobenzoquinone Drinking Water Disinfection Byproducts in T24 Cells. Toxicol. Sci., Oct 2014; 141: 335 - 343.
Guha, R. et. al. Intracellular GSH Depletion Triggered Mitochondrial Bax Translocation to Accomplish Resveratrol-Induced Apoptosis in the U937 Cell Line. J. Pharmacol. Exp. Ther., Jan 2011; 336: 206 - 214.
Maclas-Gonzalez M et al (2008) J. Nutr. 138: 903-907.
Sureh V et al. (2007) Am J. Respir. Cell Mol. Biol. 10.1165/rcmb.2006-0419OC.
For more citations of this product click here