An overview of the background for proteomics and a description of the present state of art are given with a description of the main strategies in proteomics. The advantages and limitations of the two major strategies, 2D-gel based and LC-MS based, are discussed and a combination for the two, CeLC-MS is described. A number of challenging problems which have been solved using different proteomics strategies including the advantage of organell enrichment or modifications specific peptide isolation to get deeper into the proteome are described. Finally the present status and future needs discussed.
Chromatography, High Pressure Liquid ; Electrophoresis, Gel, Two-Dimensional ; Mass Spectrometry ; Peptides ; analysis ; chemistry ; Phosphorylation ; Protein Isoforms ; analysis ; Proteome ; analysis ; Proteomics

In the past decade, relative proteomic quantification using isobaric labeling technology has developed into a key tool for comparing the expression of proteins in biological samples. Although its multiplexing capacity and flexibility make this a valuable technology for addressing various biological questions, its quantitative accuracy and precision still pose significant challenges to the reliability of its quantification results. Here, we give a detailed overview of the different kinds of isobaric mass tags and the advantages and disadvantages of the isobaric labeling method. We also discuss which precautions should be taken at each step of the isobaric labeling workflow, to obtain reliable quantification results in large-scale quantitative proteomics experiments. In the last section, we discuss the broad applications of the isobaric labeling technology in biological and clinical studies, with an emphasis on thermal proteome profiling and proteogenomics.
Proteome/metabolism* ; Proteomics/methods* ; Reproducibility of Results ; Tandem Mass Spectrometry/methods*