title: Selective precipitation of proteins from guanidine hydrochloride-containing solutions with ethanol.
abstract: The solubility of guanidine hydrochloride in ethanol and conversely the low solubility of proteins have been used as the basis for a procedure for recovering proteins from guanidine-containing solutions by selective precipitation. Yields of greater than 94% were observed with as little as 28 ng protein and of 98% for larger quantities of protein up to 20 mg/ml. The precipitations were independent of molecular weight for proteins in the range of 6-100 kDa and could be run in as little as 5 min at room temperature. Unlike the conventional desalting methods for removing guanidine, ethanol precipitation is rapid, efficient, and can be applied simultaneously to a large number of samples. The approach should have a wide range of applications.
authors.affiliation: Biogen, Inc., Cambridge, Massachusetts 02142.
authors.forename: R B
authors.initials: RB
authors.lastname: Pepinsky
mesh_terms: D001426:Bacterial Proteins / Q000302:isolation & purification; D011232:Chemical Precipitation; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000032:analysis; D000431:Ethanol; D019791:Guanidine; D006146:Guanidines; D016333:HIV Protease / Q000302:isolation & purification; D011506:Proteins / Q000302:isolation & purification*; D011994:Recombinant Proteins / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D012995:Solubility; D012996:Solutions; D013462:Sulfur Radioisotopes
chemical_list: D001426:Bacterial Proteins; D006146:Guanidines; D011506:Proteins; D011994:Recombinant Proteins; D012996:Solutions; D013462:Sulfur Radioisotopes; D000431:Ethanol; D016333:HIV Protease; D019791:Guanidine