Urea is the principal end product of nitrogen metabolism in most mammals, formed by the enzymatic reactions of the Kreb's cycle.
Urea is a mild agent usually used in the solubilization and denaturation of proteins. It is also useful for renaturing proteins from samples already denatured with 6 M guanidine hydrochloride such as inclusion bodies; and in the extraction of the mitochondrial complex. It is commonly used to solubilize and denature proteins for denaturing isoelectric focusing and two-dimensional electrophoresis and in acetic acid-urea PAGE gels. Urea is used in cell or tissue culture media to increase the osmolality. Urea has also been used as fertilizer because of the easy availability of nitrogen; in animal feeds; it is reacted with aldehydes to make resins and plastics; condensed with malonic ester to form barbituric acid; used in the paper industry to soften cellulose; used as a diuretic; enhances the action of sulfonamides; an antiseptic.
Urea in solution is in equilibrium with ammonium cyanate. The form that reacts with protein amino groups is isocyanic acid. Urea in the presence of heat and protein leads to carbamylation of the proteins. Carbamylation by isocyanic acid interferes with protein characterization because isocyanic acid reacts with the amino terminus of proteins, preventing N-terminal sequencing. Isocyanic acid also reacts with side chains of lysine and arginine residues resulting in a protein that is unsuitable for many enzymatic digests. In addition, carbamylation often leads to confusing results from peptides having unexpected retention times and masses. When performing enzymatic protein digests it is important to remove urea first. Even though some enzymes will tolerate small amounts of urea, the elevated temperature used for most reactions will lead to carbamylation during the course of the digest. The urea can be removed prior to digestion by fast reversed phase chromatography, spin columns, or dialysis.
Dissolve urea in deionized water to the desired concentration.For every 10 ml of solution, add 1 g of Amberlite® IRA-910.Stir for one hour at room temperature.
Urea is typically used at a concentration of 8 M for protein denaturation or solubilization. A final concentration of 5 M urea is commonly used in molecular biology for sequencing gels.
Grade: Ultra Pure
Purity: ≥99%
Key Applications: Denaturation, Protein Electrophoresis, SDS-PAGE
Application Areas: Proteomics
Product Type: Biochemicals
Biochemical Category: Chaotropic Agents
Density: 1.335 g/cm3 at 20°C
Relative Density: 1,335 g/mL at 25°C
Boiling Point: Decomposes at 135°C
Melting Point: 130 - 140°C
Partition Coefficient: log Pow: -2,59 - -1,59
UV/Visible Absorbance: OD260 (7M aq soln) ≤0.05, OD280 (7M aq soln) ≤0.05
pH: 8.5 ± 1.0 (7M aq soln)
Conductivity: ≤100 uMhos
Foreign activity: Cyanate, DNase, RNase, Cyanate, protease none detected
Heavy Metals: Lead ≤1 ppm, Iron ≤1 ppm and copper ≤1 ppm
Solubility: One gram dissolves in 1 mL water, 10 mL 95% ethanol, 1 mL boiling 95% ethanol, 20 mL absolute ethanol, 6 mL methanol, 2 mL glycerol; Soluble in concentrated hydrochloric acid; almost insoluble in chloroform, ether.
Storage & Handling: Room Temperature