Glutathione

For Laboratory Research Use Only — Not for Human or Veterinary Use.

Standard (< 1,000 vials)$240/kit

Volume (1,000+ vials)$140/kit

Quantity (kits)

= 10 vials

Minimum order: 100 vials total. Mix and match across all products.

I confirm this order is for laboratory research use only.For Laboratory Research Use Only — Not for Human or Veterinary Use. By checking this box you affirm this product will not be used for human or animal administration.

Specifications

CAS Number	70-18-8
Molecular Formula	C10H17N3O6S
Molecular Weight	307.32 g/mol
Purity	≥98% (HPLC)
Form	Lyophilized Powder
Storage	-20°C, desiccated, protected from light
Reconstitution	Bacteriostatic water

Certificate of Analysis

Lot documentation

Every production lot is independently third-party tested. A batch-specific Certificate of Analysis — documenting HPLC purity, mass spectrometry identity confirmation, and net peptide content — is issued with every shipment. View a sample COA to see the format.

View Sample COA About our testing →

Research context

A tripeptide joined through an unusual gamma-linkage, carrying a free thiol that begins oxidising the moment it dissolves. The ratio of reduced to oxidised form is the specification that matters.

Structure and chemical class

Glutathione is the tripeptide glutamate-cysteine-glycine, but the bond between the first two residues is not the ordinary one. Glutamate is joined through its side chain carboxyl rather than its alpha carboxyl, making the linkage a gamma-peptide bond, and the molecule is therefore not a substrate for the aminopeptidases that process conventional peptides.

That single structural quirk explains its cellular persistence. Only gamma-glutamyl transpeptidase cleaves the linkage, and that enzyme is located on the outer face of the cell membrane, so intracellular glutathione is effectively protected from proteolysis. It is also why the molecule is synthesised by two dedicated ligases rather than by the ribosome.

The functional group is the cysteine thiol. Two molecules oxidise to a disulfide-linked dimer, and the ratio between the reduced monomer and that dimer defines the redox potential of the cellular thiol pool, which is one of the most widely measured parameters in redox biology.

Findings in the published research literature

The reduced and oxidised couple is used throughout cell biology as the primary indicator of intracellular redox state, and a large methodological literature concerns measuring it without perturbing it, since the couple re-equilibrates rapidly during sample preparation.

Enzymatically, the tripeptide is a co-substrate for two major families. Glutathione peroxidases use it to reduce peroxides, and glutathione S-transferases conjugate it to electrophilic compounds, which is the first step of the mercapturic acid pathway. Both families appear extensively in cultured cell and rodent literature, and glutaredoxin-mediated protein deglutathionylation has developed into a substantial field of its own.

Analytical verification

The number to look for on a lot analysis is the content of the oxidised dimer, not the purity percentage alone. The dimer has a mass of two daltons less than twice the monomer, is chromatographically well separated, and is the impurity that accumulates in any thiol compound with time and air exposure. A purity figure that does not report it separately leaves the most likely contaminant unquantified.

Free thiol content is measured directly with 5,5-dithiobis-2-nitrobenzoic acid, which releases a yellow chromophore stoichiometrically and gives a rapid bench assay for how much of the material is genuinely in the reduced form. HPLC with electrochemical detection and mass spectrometry are the higher-resolution methods, and enzymatic recycling assays quantify total and oxidised pools separately.

Autoxidation is fast enough to matter during the analysis itself. Thiol oxidation is catalysed by trace transition metals and accelerates sharply above neutral pH, so a sample prepared in unacidified, unchelated buffer can oxidise measurably while waiting to be injected.

Handling and storage

Solubility	Freely soluble in water, giving an acidic solution.
Reconstitution	Prepare fresh and use promptly. Degassed water, a mildly acidic pH and a chelator such as EDTA together suppress metal-catalysed autoxidation.
Storage	Solid at -20C, desiccated and protected from light. The dry solid is far more stable than any solution of it.
Stability	Oxidation of the thiol to the disulfide dimer is the governing degradation route and proceeds in solution on a timescale of hours to days depending on pH, temperature and metal contamination. Stored reconstituted material should be assumed to have shifted toward the oxidised form unless it has been measured.