• USA Home
  • X1875 - Xanthine Oxidase from bovine milk

X1875 Sigma

Xanthine Oxidase from bovine milk

Grade I, ammonium sulfate suspension, ≥0.4 units/mg protein

Synonym: XOD, Xanthine:oxygen oxidoreductase



Related Categories 1.1.x.x Acting on hydroxyl groups, 1.x.x.x Oxidoreductases, Biochemicals and Reagents, Cell Biology, Enzyme Class Index,
type   Grade I
form   ammonium sulfate suspension
foreign activity   uricase ≤0.5%
shipped in   wet ice
storage temp.   2-8°C


Analysis Note

Protein determined by biuret

General description

Formerly E.C.


5, 25 units in serum bottle

Unit Definition

One unit will convert 1.0 μmole of xanthine to uric acid per min at pH 7.5 at 25 °C. Approx. 50% of the activity is obtained with hypoxanthine as substrate.

Physical form

Suspension in 2.3 M (NH4)2SO4 containing 1 mM sodium salicylate

Biochem/physiol Actions

Xanthine oxidase is a molybdenum-containing enzyme that is found in the cytosol, and may be strongly inhibited by flavonoids. It plays a vital role in the metabolism of some drugs, as well as purines and pyrimidines. It is also known to be a biological source of reactive oxygen species.

Xanthine oxidase was shown to be involved in the reduction of cytochrome c by the generation of superoxide anions following the oxidation of xanthine. These free radicals are responsible for reducing cytochrome c.

Price and Availability

All labs need water

Biomedical Applications
Safety & Documentation

Safety Information

NONH for all modes of transport
WGK Germany 
Protocols & Articles


Ammonium Sulfate Suspensions - Technical Note

Note that for an ammonium sulfate suspension, most of the enzyme will be in solid form. It is likely that only negligible amounts of enzyme will be in the ammonium sulfate solution.
Keywords: Enzyme activity


Enzymatic Assay of Superoxide Dismutase

This procedure applies to all products that have a specification for superoxide dismutase activity by enzymatic determination.
Keywords: Catalysis, Reductions

Related Content

Enzymes & Proteins

Application Index | Enzyme Index | Substrate Index | Inhibitor Index | Cofactor Index | Lectin Index
Keywords: Cell signaling, Diagnostic, Drug discovery, Molecular biology

Peer-Reviewed Papers


Related Products

related product

Product #


Add to Cart

08168 Timestrip Plus 8 °C

Technical Service:

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Bulk Ordering & Pricing:

Need larger quantities for your development, manufacturing or research applications?