Imaging mass spectrometry using peptide isoelectric focusing

Rapid Commun Mass Spectrom. 2008 Sep;22(17):2667-76. doi: 10.1002/rcm.3658.


Imaging Mass Spectrometry (IMS) has emerged as a powerful technique in the field of proteomics. The use of Immobilized pH Gradient-IsoElectric Focusing (IPG-IEF) is also a new trend, as the first dimension of separation, in shotgun proteomics. We report a combination of these two outstanding technologies. This approach is based on the separation of shotgun-produced peptides by IPG-IEF. The peptides are then transferred by capillarity to a capture membrane, which is then scanned by the mass spectrometer to generate MS images. This high-throughput methodology allows a preview of the sample to be obtained in a single day. We report the application of this new pipeline for differential comparison of the membrane proteome of two different strains of Staphylococcus aureus bacteria in a proof-of-principle experiment.

MeSH terms

  • Isoelectric Focusing
  • Membrane Proteins / chemistry*
  • Peptide Mapping*
  • Proteomics / methods*
  • Species Specificity
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / instrumentation*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Staphylococcus aureus / chemistry*
  • Staphylococcus aureus / classification
  • Tandem Mass Spectrometry / instrumentation
  • Tandem Mass Spectrometry / methods


  • Membrane Proteins