Peptide mass fingerprinting (PMF) (also known as protein fingerprinting) is an analytical technique for protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 identification that was developed in 1993 by several groups independently. In this method, 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

Electrospray

The name electrospray is used for a device that employs electricity to disperse a liquid or for the fine aerosol resulted in this process. The method is sometimes improperly called electrohydrodynamic atomization. High voltage is applied to a liquid supplied through an emitter...

. These masses are then compared to either a database containing known protein sequences or even the genome.