Proteomics has largely been practiced through the separation of proteins in two dimensional gel electrophoresis. One one axis, the proteins are separated by [molecular weight]?, and in the other, they are separated by isoelectric point. The gel is dyed with [Coomasie staining]? or silver to highlight the proteins. Spots on the gel are proteins that have migrated to specific locations.
The mass spectrometer has augmented proteomics. [Mass mapping]? identifies a protein by cleaving it into short peptides and then deduces the protein's identity by matching the observed peptide masses against a [sequence database]?. Tandem mass spectrometry, on the other hand, can get sequence information from individual peptides by isolating them, colliding them with a nonreactive gas, and then cataloging the fragment ions produced.
![[Home]](wikipedia.png)