ABSTRACT
Quantitation LC-MS Data .................................................................54 2.10 Future Challenges.......................................................................................... 55 Acknowledgments .................................................................................................... 57 References ................................................................................................................ 57
The liquid chromatography (LC)-mass spectrometry (MS) analysis of peptides has become an increasingly routine method for proteomics-the study of the entire complement of proteins, for example, expressed by a cell under a specifi c set of conditions at a specifi c time. Mixtures of peptides, such as those generated from enzymatic (e.g., trypsin) digestion of globally recovered proteins (i.e., a proteome), are typically very complex and >100,000 different molecular species may be observable using MS detection [1]. LC separations implemented prior to MS for broad protein identifi cation have three major roles: (1) to isolate individual components or reduce complexity as much as possible, (2) to increase sensitivity by concentrating the components into narrow zones prior to MS, and (3) to eliminate or displace interfering species (e.g., salts and polymers) that may be present in proteomics samples.
