Preanalytical Sample Simplification

This multidimensional protein identification technology (MudPIT) specifically incorporates a strong cationic exchange (SCX) column in tandem with an RP column to achieve maximal resolution and exquisite sensitivity. MudPIT is effective for studying complex proteomes such as mammalian cellular samples. It has been applied to large-scale protein characterization with identification of up to 1484 proteins from yeast in a single experiment.12 

MS instruments measure the mass-to-charge ratio (m/z) values of the smallest of molecules very accurately. In addition, the development of translated genomic databases and specialized software algorithms that rapidly search MS data against theoretical spectra of known or predicted proteins within databases is an important component that greatly facilitated the emergence of mass spectrometry-based proteomics as a key approach for large-scale proteomic analysis.15 

The basic components of an MS instrument are an ionization source, a mass analyzer, and a detector. The ionization source generates ions from the sample to be analyzed. The mass analyzer 

FIGURE 15.1 Overview of configuration of MS and MS-based proteomic analysis. Proteins are extracted from biologic samples and fractionated by a variety of separation methods including gel separation, HPLC, and capillary electrophoresis. The common ion sources and mass analyzers used are indicated. 

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