Patent ID: 6875617

Claim:
A method of preparation of protein sample solution for analysis, wherein the protein sample solution contains one or more non-protein agents selected from the group consisting of an anionic detergent, a cationic detergent, a non-ionic detergent, a zwitterionic detergent, a sulfobutane, a lipid, a polysaccharide, a polyphenol, a tannin, an alkaloid, a pigment, a reducing agent, a protein denaturant, an amine, HEPES, a TRIS buffer, and a salt, wherein after the preparation of the protein sample the protein in the sample is quantitatively recovered and is without interference from the non-protein agents originally present in the sample, comprising the following steps: (a) treating the protein sample solution with a solution that comprises an acidic agent and a salt that precipitates the detergents selected from the group consisting of sodium salt, potassium salt, calcium salt, magnesium salt and guanidine salt so as to precipitate the protein; (b) centrifuging the precipitated protein sample solution to form a tight protein pellet at the bottom of the tube, removing and discarding the supernatant and collecting said protein pellet; (c) suspending said protein pellet in at least one medium selected from a group consisting of a mixture of aqueous-organic solvent and an organic solvent; (d) centrifuging said suspended protein and collecting a washed protein pellet; and (e) solubilizing the washed protein pellet in a protein pellet solubilization buffer, wherein the solubilization buffer is provided with an acid neutralizing agent in a sufficient amount to substantially neutralize the acid captured in the protein pellet to facilitate a desired protein solubilization.