Methodology Report

A Proteomic Approach for Plasma Biomarker Discovery with iTRAQ Labelling and OFFGEL Fractionation

Figure 3

Analysis of the quality of the OFFGEL fractionation of iTRAQ-labelled peptides from immunoaffinity depleted (IM) or hexapeptide ligand library treated (PM) plasma. The average experimental pI of all peptides in each of the 24 OFFGEL fractions after filtering for false positive is presented as bars. Error bars indicate the SD of each fraction’s experimental pI. The broken line is based on the theoretical pI values for an IPG strip of 24 cm, pH 3–10 provided by Agilent Technologies.