The "workhorse" of proteomics is bottom-up analysis, and the majority of proteomics workflows involve the use of a bottom-up strategy. In this approach, proteins are first subjected to enzymatic digestion typically using trypsin. This generates peptides, which are then separated using one or more LC technologies. The LC eluent is charged via electrospray ionization, after which the peptides are fragmented within the mass spectrometer and identified.
Deriving high quality peptide identification from complex biological samples over a wide dynamic range is a challenging but necessary aspect of bottom-up proteomics. Fortunately, high-resolution, accurate-mass (HRAM) Thermo Scientific Orbitrap mass spectrometers offer advanced mass resolution and accuracy, as well as fragmentation and speed. Multiple fragmentation techniques (CID, HCD, ETD, and EThcD) ensure maximal sequence coverage of analyzed peptides. These combined Orbitrap system qualities enable higher and more detailed bottom-up protein identifications from complex proteomics samples than ever before.
Once the raw analysis files are generated, Thermo Scientific proteomics software mines the rich HRAM Orbitrap MS data and converts large data sets into meaningful insights.