Figure 1.

The workflow for the two proteomic approaches used to quantify serum proteins from patients with oral squamous cell carcinoma (OSCC). (A) In the first approach, we quantified serum proteins between OSCC and healthy control subjects by performing in-solution digestion of serum proteins, isobaric tags for relative and absolute quantification (iTRAQ) labeling of the resulting peptides, SCX (strong cation exchange) separation of labeled peptides and finally capillary LC with MS/MS analysis of the peptides; and (B) In the second approach, we first separated serum proteins with SDS-PAGE. The gel-separated proteins were then digested with trypsin and the resulting peptides were labeled with iTRAQ and analyzed with LC-MS/MS for protein quantification.