Evaluation of Formalin Fixed Paraffin Embedded Tissues for the Extraction and Comparison of Peptide Phosphorylation

摘要

Recent publications have demonstrated the promise of proteomic analyses of formalin fixed paraffin embedded (FFPE) tissues for the discovery of putative disease biomarkers. Phosphorylation is a post-translational modification (PTM) that holds great importance in many clinical applications. Literature reviews show little data on the recovery of phosphorylated peptides from formalin fixed paraffin embedded (FFPE) samples. We have attempted to determine if this PTM can be carried through a full antigen retrieval process culminating in sequence identification via LC MS/MS. We have also attempted to reconcile relative retrieval rates between freshly processed cells and those fixed for analysis to obtain a semi-quantitative comparison of phosphorylation rates. This will allow us to determine if phosphorylation is consistent from pre fixation materials, through fixation and beyond.