Peptide mass fingerprinting (PMF) is an analytical technique for protein identification. Basically, the unknown protein of interest is first cleaved into smaller peptides, whose absolute masses can be accurately measured with a mass spectrometer such as MALDI-TOF or ESI-TOF. Then these masses are compared to either a database containing known protein sequences or even the genome sequence which can be translated into proteins through computer programs. Then the absolute masses of the peptides from each protein are calculated theoretically for mass comparison between the peptides of the unknown protein and the theoretical peptide masses of each protein to find the best match. Is protein identification by peptide mass fingerprinting useful?