Peptide fractionation of the digested SH-SY5Y proteins by OFFGEL

Efficient separation in the peptide level is crucial to the protein identification based on the shotgun strategy. The ability of peptide fractionation of OFFGEL was investigated by tryptic digested peptides of SH-SY5Y. 24 fractions were obtained after OFFGEL fractionation. Each fraction was performed by capillary high performance liquid chromatography electrospray mass spectrometry. 83. 7% peptides were unique to one fraction and average isoelectric point values in each fraction were basically consistent with the expected values. Furthermore, the standard derivations of isoelectric point values were small in the low pH range. OFFGEL could fractionated 16 samples simultaneously, recovery the sample from solution directly and facilitate to the detection by mass spectrometry. OFFGEL can play more and more important role in the peptide separation.