Proteins and peptides are becoming increasingly important as therapeutic agents and indicators of disease. Their ultimate success in this role rests on our ability to quantitate them both accurately and rapidly, especially from complex matrices. Though traditional immunoassay-based quantitation assays are widely used in this role, they are hampered by a lack of absolute structural specificity, as well as long and laborious assay development, multiplexing limitations, and difficulty with internal standardization.
Analysis via mass spectrometry addresses these limitations. MS-based methods allow for exquisitely specific target identification, with the potential to incorporate stable isotope–labeled standards for very precise quantitative performance. Mass spectrometry is also uniquely able to measure many things without interference among them, using methods that are rapidly configurable.