Basics of Mass Spectrometry and Its Applications in Biomarker Discovery

Mass spectrometry (MS) is the method of choice for both qualitative and quantitative high-throughput proteome analysis. In the early years, mass spectrometry was used only for small molecule analysis. However, advances in ionization sources, mass analyzers, and mass detectors made MS the central force in proteomics technologies. Starting from its use in peptide mass fingerprinting (PMF), MS has evolved greatly over the last two decades and now finds use in shotgun proteomics where thousands of proteins can be quantified at once. Currently, MS finds use in targeted proteome analysis and is widely used for biomarker discovery in cancer, diabetes, cardiovascular diseases, and infectious diseases worldwide to diagnose the diseases at the early stage or to unravel the mechanism of pathogenesis. The applications of MS have not been limited to proteomics and have moved to metabolomics, lipidomics, tissue imaging, in understanding posttranslational modifications (PTMs), etc. This chapter provides details of mass spectrometry and its applications in biomarker discovery.