Protein identification from two-dimensional gel electrophoresis by connecting ZipTip with a home-assembled nanoflow system

Mass spectrometry (MS) is a powerful technique for protein identification in proteomic research. Two-dimensional gel electrophoresis (2-DE) combined with MS is a significant method for protein separation and identification. For protein identification, peptide sequencing is usually carried out by an effective but expensive nano-flow liquid chromatographic system combined to tandem mass spectrometry (MS/MS). However, protein identification based on such method is time-consuming, and contamination may occur as a result of column overloading. In this study, we establish an alternative nanoscale system for protein identification using MS/MS. The system consists of several devices that can be purchased from commercial sources and can be connected to an electrospray ionization quadrupole-time of flight (ESI-Q-TOF) MS in order to analyze proteins from 2D gels. This inexpensive strategy provides an attractive alternative method for rapid identification of proteins using a nanospray source. In addition, the device is disposable so that contamination is avoided. It is shown that peptide sequencing based on this device using ESI-Q-TOF MS is accomplished within 10 min.