Peptide mass fingerprinting

Peptide Mass Fingerprinting (PMF) is an analytical technique for identifying unknown protein. Proteins to be identified is first digested into peptides, whose absolute mass can be accurately analyzed by a mass spectrometer, such as MALDI-TOF or ESI-TOF. MALDI is more preferred in PMF analysis, as it has a wide sequence coverage and can analyze a large amount of sample at the same time. The peptide mass are compared to database containing the theoretical peptide masses of all known protein sequences. The match with the highest score was considered to be the identity of the unknown protein.