Multidimensional protein identification technology.

Over the past years, large-scale analysis of proteomes gained increased interest to obtain a fast but nevertheless comprehensive overview about cellular protein content. While a complete proteome cannot be covered using current technologies because of its enormous diversity, subfractionation to reduce the complexity has become mandatory. While 2D-PAGE is well established as a high-resolution protein separation technique, it suffers from drawbacks, which can be overcome by using peptide separation methods based on multidimensional liquid chromatography. One of these technologies is multidimensional protein identification technology (MudPIT). It consists of two orthogonal separation systems--strong cation exchange (SCX) and reversed phase (RP)--coupled online in an automated fashion to mass spectrometric detection. This method offers the possibility to analyze high-complex peptide mixtures in a single experiment.