Proteomic analysis involves fractionating and enriching cells or tissue to isolate proteins, then further breaking the proteins into peptides. The peptides are separated using chromatography and introduced into a mass spectrometer to determine their mass-to-charge ratios. Data-dependent acquisition is used to automatically select peptides for fragmentation and sequencing to identify the proteins present. Proteomics provides information about protein expression levels, post-translational modifications, interactions, and dynamics that complement genomics and transcriptomics data.