Matrix-assisted desorption ionisation time-of-flight mass spectrometry (MALDI-TOF) is a powerful technique used in one method of identifying proteins. The protein purified from a sample is first broken (digested) into shorter fragments by the selective action of an enzyme, usually trypsin. The mixture of fragments is then analysed by mass spectrometry to give a spectrum, or "fingerprint", showing the masses of the fragments. By comparing with the spectra predicted for possible proteins, the actual protein can be identified. The utility of the technique is dependent on the large DNA sequence databases that have been assembled for several orgainisms. These can be used to predict the mass spectrum fingerprints of proteins coded by the DNA
The ProMS product automates the process of transfering samples of digested protein and matrix chemicals onto special targets for insertion into the mass spectrometer. It also includes a purification facility that removes salts that can contaminate the samples and which otherwise interfere with the mass spectrometery.
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For information on the ProMS instrument: Genomic Solutions Inc