Nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS) has become an essential tool in the field of proteomics. In fact, its sensitivity has advantages over conventional LC-MS/MS that allow the analysis of peptide mixtures in sample-limited situations (e.g., proteolytically digested proteins isolated by two-dimensional gel electrophoresis). Technical challenges, associated with low flow rates of the chromatographic separation, make this technology still difficult to run routinely. Here, we describe a nano LC-MS/MS setup that allows several weeks of continuous operation for the analysis of peptides derived by enzymatic digestion of either purified proteins or moderately complex protein mixtures.
