|Show all terms|
Matrix-Assisted Laser Desorption/Ionization Time Of Flight Mass Spectrometry (MALDI-TOF MS)
The instrument in the image belongs to the Department of Biomedical Sciences and Veterinary Public Health at the Swedish University of Agricultural Science (SLU). Lise-Lotte Fernström (+46 18 672389) and Lars Frykberg are responsible for the equipment and it is possible to get samples analyzed.
Mass spectrometry based on the MALDI-TOF means that the sample to be analyzed, is adsorbed to some type of carrier material (matrix). The sample is then irradiated with laser UV light, so that the molecules in the sample are broken into charged fragments (ionization), which are thrown towards a detector. The time it takes for the fragment to reach the detector (time of flight) is measured. The time is dependent on fragment size and charge. Also very large molecules (proteins and nucleic acids) can be fragmented and ionized in this way. Large molecules give rise to many fragments and a characteristic mass spectrum, which can be used for identification.
More recently MALDI-TOF MS has been used for the identification of bacteria. One can perform these analyzes directly on bacterial colonies and the resulting mass spectrum is then compared with stored mass spectra of known bacteria. Thus, you will get an analytical response within a minute and the method is considered to be very reliable. The more mass spectra of known bacteria you have to compare with, the safer the method will be.
MALDI-TOF MS is already used in some laboratories for veterinäry bacteriology and many researchers believe that this technique will be tomorrow's routine method for identification of bacteria. The instrument is still very expensive, but material costs are low.