Merck, 1.08487, Urea

Application
Used for the denaturation of proteins and as a mild solubilization agent for insoluble or denatured proteins. Useful for renaturing proteins from samples already denatured with 6 M guanidine chloride such as inclusion bodies. May be used with guanidine hydrochloride and dithiothreitrol (DTT) in the refolding of denatured proteins into their native or active form.
Analysis Note
Assay (ex N): 99.0 - 100.5 %
Assay (ex N, calc. on dried substance): 99.0 - 101.5 %
Purity (DSC (differential scanning calorimetry)): ≥ 99.5 %
Identity (IR-spectrum): passes test
Appearance of solution (10 %; Wasser; colour): colourless
Appearance of solution (10 %; Wasser; clarity): clear
In water insoluble matter: ≤ 0.003 %
Acidity, Alkalinity: ≤ 0.0005 meq/g
Melting point (DSC): 132 - 135 °C
NH₄ (Ammonium): ≤ 0.0500 %
Chloride (Cl): ≤ 0.0005 %
Sulfate (SO₄): ≤ 0.001 %
Heavy metals (as Pb): ≤ 0.0004 %
Biuret: ≤ 0.05 %
Sulfated ash (600 °C): ≤ 0.005 %
Cu (Copper): ≤ 0.0001 %
Fe (Iron): ≤ 0.0001 %
Pb (Lead): ≤ 0.0002 %
Loss on Drying (105°C): ≤ 1.0 %
Corresponds to ACS, Reag. Ph Eur
Other Notes
Replaces: UX0065-1