Method and system of identifying and quantifying a protein

Abstract

Methods and system for identifying and/or quantifying a protein are provided herein.

What is claimed is: 
     
         1 . A method for detecting a protein in a sample, said method comprising:
 contacting said sample to a chromatographic system having a mixed-mode size exclusion chromatography resin with a hydrophobic interaction functionality which results in a mixed-mode separation;   washing said mixed-mode size exclusion chromatography resin using a mobile phase to provide an eluent including the protein; and   detecting the protein in said eluent using a mass spectrometer, wherein the mass spectrometer is coupled to the chromatographic system.   
     
     
         2 . The method of  claim 1 , wherein the mobile phase used to elute the protein contains ammonium acetate, ammonium bicarbonate, or ammonium formate, or combinations thereof. 
     
     
         3 . The method of  claim 1 , wherein the mobile phase used to elute the protein has a total concentration of less than about 600 mM of ammonium acetate and ammonium bicarbonate. 
     
     
         4 . The method of  claim 1 , wherein the mobile phase used to elute the protein has a flow rate of about 0.2 ml/min-about 0.4 ml/min. 
     
     
         5 . The method of  claim 1 , wherein the amount of the sample loaded onto the mixed-mode size exclusion chromatography resin is about 10 μg to about 100 μg. 
     
     
         6 . The method of  claim 1 , wherein the protein is a product-related impurity. 
     
     
         7 . The method of  claim 1 , wherein the protein is a homodimer. 
     
     
         8 . The method of  claim 1 , wherein the protein is an antibody. 
     
     
         9 . The method of  claim 8 , wherein the antibody is a fusion protein. 
     
     
         10 . The method of  claim 1 , wherein the mass spectrometer is a native mass spectrometer. 
     
     
         11 . A method for detecting a protein in a sample, said method comprising:
 contacting said sample to a chromatographic system having a mixed-mode size exclusion chromatography resin with a charge-charge interaction functionality which results in a mixed-mode separation;   washing said mixed-mode size exclusion chromatography resin using a mobile phase to provide an eluent including the protein; and   detecting the protein in said eluent using a mass spectrometer, wherein the mass spectrometer is coupled to the chromatographic system.   
     
     
         12 . The method of  claim 11 , wherein the mobile phase used to elute the protein contains ammonium acetate, ammonium bicarbonate, or ammonium formate, or combinations thereof. 
     
     
         13 . The method of  claim 11 , wherein the mobile phase used to elute the protein has a total concentration of less than about 600 mM of ammonium acetate and ammonium bicarbonate. 
     
     
         14 . The method of  claim 11 , wherein the mobile phase used to elute the protein has a flow rate of about 0.2 ml/min-about 0.4 ml/min. 
     
     
         15 . The method of  claim 11 , wherein the amount of the sample loaded onto the mixed-mode size exclusion chromatography resin is about 10 μg to about 100 μg. 
     
     
         16 . The method of  claim 11 , wherein the protein is a product-related impurity. 
     
     
         17 . The method of  claim 11 , wherein the protein is a homodimer. 
     
     
         18 . The method of  claim 11 , wherein the protein is an antibody. 
     
     
         19 . The method of  claim 18 , wherein the antibody is a fusion protein. 
     
     
         20 . The method of  claim 11 , wherein the mass spectrometer is a native mass spectrometer.