MALDI-TOF | By Linda L. Leake, MS
As general manager of Mérieux NutriSciences, Wendy McMahon, MS, CFS, oversees the company’s Silliker Food Science Center (SFSC) contract research laboratory, Crete, Ill.
McMahon believes matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectroscopy (MS) is an important tool for bacterial and fungal identification in food laboratories today. “It’s really used for determining unknown organisms, mostly spoilage and contaminations, with mold being a good example,” she points out.
Available commercially for less than 10 years, MALDI is three-step soft ionization technique that allows the analysis of biopolymers such as DNA, proteins, peptides, and sugars, and also large organic molecules. The TOF is the type of mass spectrometer most widely used with MALDI, primarily because of its large mass range.
McMahon says it’s interesting that the microbiology world is using MS for bacterial identification, since MS is a tool used for chemical analysis. “Chemists get a kick out of this,” she quips.