Quantitative proteomics by metabolic labeling with stable isotopes

Protein quantification based on mass spectrometry (MS) is an emerging application in the field of proteomics. This approach involves not only the identification of proteins on a global scale, but also the accurate quantification of their expression levels. Over the past few years several techniques have been developed to achieve this aim, most of which incorporate the labeling of proteins with stable isotopes, including chemical (in vitro) derivatization techniques such as isotope-coded affinity tags (ICATs). Recently, however, there has been an increase in the development of methods for the metabolic (in vivo) labeling of organisms ranging from bacteria to fruitflies. These methods have numerous potential applications in biomedical research.