Page 15 - Microorganism Species Analysis
P. 15

MALDI-TOF MS                                                                                                                                                                                                         MALDI-TOF MS
                                                 Direct Measurements of Microorganisms
            Microorganism Solutions                                                                                                                                                                                              Microorganism Solutions




                     Direct Measurements of Microorganisms Using the MALDI-TOF MS AXIMA Series                                            Data
                     The conventional analysis of a microorganism-derived component required the extraction, purification, and analysis of the
                     microorganism (or culture fluid) from which the component is derived. All conventional methods were complex and       Direct Measurement of Microorganisms Using the MALDI-TOF MS AXIMA Series
                     time-consuming.                                                                                                                                                                                                                   Microorganism Species  Observation of
                     In contrast, MALDI-TOF MS can analyze a wider range of compounds and their states.                                    Test and research flow
                     This feature allows high throughput and low running costs for analysis of microorganism-derived components for the    1. Pick up some of the bacteria from a single colony pre-cultivated on the plate.
                     measurement of entire microorganisms.                                                                                 2. Directly apply the bacteria sample and matrix reagent to the AXIMA MALDI sample plate.
            Observation of
                     A new method using MALDI-TOF MS (Intact-Cell MALDI-TOF Mass Spectrometry) is attracting attention for the             3. Perform mass spectrometry using the MALDI-TOF MS AXIMA Series.
          Microorganism Species
                     measurement of entire microorganisms without complex pretreatment.



                        Features of Direct Measurement of Microorganisms Using the
                        MALDI-TOF MS AXIMA Series
                         MS analysis possible by simply mixing the microorganism with the matrix solution; no complex sample pretreatment                                                                                                              Microorganism Species  Identification of
                         required
                         Analysis complete in just two minutes after the start of measurements
                         Permits high-throughput analysis (>1,000 samples/day)
            Identification of
                         No pretreatment reagent required – low running costs
          Microorganism Species




                         Sample microorganisms (bacteria)                     Apply bacteria sample to sample plate
                                                                                                                                                                                            m/z
                                                                                                                                                                      Fig. 1 MS Spectrum of Escherichia coli (NBRC 3972 Strain)                        Specific Microorganisms  Detection of


            Detection of
                                                                                                                                           Fig. 1 shows the direct measurements of Escherichia coli (NBRC 3972 strain). In particular, the ribosomal subunit
                                                                                                                                           proteins (Lxx and Sxx peaks on the spectrum) in the bacteria were detected. In addition, multiple ions derived from
                                                                                                                                           peptides and lipids can be detected directly from the microorganism without extraction or purification.
          Specific Microorganisms











          Components
                         Mass spectrometry                                                                                                                                                                                                             Components  Analysis of Microorganism-Derived


            Analysis of Microorganism-Derived








                                                                                                                                                                              Fig. 2 MS Spectra for Various Bacteria                                   Other Applications
                                                                                                                                           A comparison of the measurement results for various bacteria samples in Fig. 2 shows that distinctive spectral
                          AXIMA Performance (MS/MS:CID/PSD)   AXIMA Confidence (MS/MS:PSD)   AXIMA Assurance (MS:Linear)                   patterns are obtained according to the bacteria species.
          Other Applications
                          Laser Desorption Ionization Time-of-Flight   Laser Desorption Ionization   Laser Desorption Ionization
                          Mass Spectrometer                   Time-of-Flight Mass Spectrometer  Time-of-Flight Mass Spectrometer
                                                                                                                                           (Data supplied by Prof. K. Tanamoto and Associate Professor M. Muroi, Faculty of Pharmacy, Musashino University and Mr. Y. Nakagawa,
                                                                                                                                           National Institute of Technology and Evaluation)
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