Mass spectroscopic method for comparing protein levels in two or more samples

摘要

The present invention provides a new and improved method for quantitative determination and/or identification of proteins in a sample. In one aspect, the invention provides a mass spectroscopic method for comparing protein levels in two or more samples by differentially isotopically labeling each sample's proteins' N- or C-termini. In another aspect, the invention provides a mass-spectroscopic method for identifying a sample as source for a protein from a mixture of two or more samples by differentially isotopically labeling each sample's proteins' N- or C-termini.