The 9-protein mix consists of the 20pmol amount of the following proteins: Human IgG (gi 164503), Rabbit glycogen phosphorylase (gi 7427923), Bovine glutamate dehydrogenase (gi 118533), E.coli alpha-amylase precursor (gi 113811), Human glucoamylase (gi 113791), Bovine catalase (gi 115698), Bovine lactoperoxidase (gi 129823), Bovine albumin (gi 1351907), Bovine serotransferrin (gi 2501351). Individual trypsinized and carboxymethylated protein digests were purchased from MICHROM Bioresources. Tandem mass spec dataset was acquired via 10 discrete ammonium chloride elutions off the BioBasic SCX column, each followed by a continuous reverse phase elution off the BioBasic C18 column for 85min with the final acetonitrile concentration of 45%. The total number of acquired MS/MS scans is 20,592.