Mass Spectrometry Facility assists researchers in experiments in which the accurate measurements of mass are important. The variety of services include peptide mapping, measurement of adduct formation on proteins & DNA, mass of mutant proteins, fidelity of recombinant proteins, peptide identification during the purification of synthetic peptides, identification of drugs & their metabolites, oxygen 18 & oxygen 16 isotope exchange experiments, identification of invivo & invitro phosphorylation sites, and protein processing. We can use the mass information of the peptides of a proteolytic digest to identify a protein from the databases. Tandem mass spectrometry is used to partially microsequence peptides using samples that cannot be obtained in sufficient quantities for Edman degradation sequencing methods. These approaches are important to current investigations of gene regulation, signal transduction and gene identification. Services provided include peptide sequencing and biomarker discovery.