Two-Dimensional Electrophoresis and Identification by Mass Spectrometry.

Two-dimensional electrophoresis (2-DE) is a classical separation technique for complex protein mixtures based on a first-separation step by isoelectric point (pI) followed by SDS-PAGE. Due to its high resolving power (including protein isoforms) and the capability to display post-translational modifications, 2-DE has been the technique of choice in many studies focused in characterizing allergens. In this chapter, we describe a standard protocol which enables efficient protein separation and subsequent protein identification by tandem mass spectrometry (MALDI-MS/MS).