Imaging mass spectrometry: principle and application

Abstract

Imaging mass spectrometry (IMS) is twodimensional mass spectrometry to visualize the spatial distribution of biomolecules, which does not need either separation or purification of target molecules, and enables us to monitor not only the identification of unknown molecules but also the localization of numerous molecules simultaneously. Among the ionization techniques, matrix assisted laser desorption/ionization (MALDI) is one of the most generally used for IMS, which allows the analysis of numerous biomolecules ranging over wide molecular weights. Proper selection and preparation of matrix is essential for successful imaging using IMS. Tandem mass spectrometry, which is referred to MS n , enables the structural analysis of a molecule detected by the first step of IMS. Applications of IMS were initially developed for studying proteins or peptides. At present, however, targets of IMS research have expanded to the imaging of small endogenous metabolites such as lipids, exogenous drug pharmacokinetics, exploring new disease markers, and other new scientific fields. We hope that this new technology will open a new era for biophysics.

Involvement of type VI secretion system in secretion of iron chelator pyoverdine in Pseudomonas taiwanensis

“…3a ). Using MALDI-IMS, the spatial distribution of molecules can be visualized without labeling 23 . Plates with wild-type P. taiwanensis gave a pyoverdine signal at m/z 1044.…”

Sixty-five years since the New York heat wave: Advances in sweat testing for cystic fibrosis

“…73 However, the recent technological advances for elemental analysis using inductively coupled plasma mass spectrometry (ICP-MS) has been applied to sweat chloride analysis. 56,74,75 Mass spectrometry is often considered to be an appropriate technology base for the development of primary reference methods. As such, development of an ICP-MS primary reference method may well provide the reference anchor needed for sweat chloride analysis which routine methods could be traceable to.…”

“…Such a method which is specific for the levels and matrix of sweat chloride is currently not recognized . However, the recent technological advances for elemental analysis using inductively coupled plasma mass spectrometry (ICP‐MS) has been applied to sweat chloride analysis . Mass spectrometry is often considered to be an appropriate technology base for the development of primary reference methods.…”

Software Tools of the Computis European Project to Process Mass Spectrometry Images

“…[16][17][18][19][20] The range of molecules was considerably extended so that it is now possible to measure molecular weights above 200 kDa, 21,22 to reach a mass measurement accuracy of subparts per million 23,24 and to detect a particular compound in the order of the low femtomoles per square micrometer. 25 Datasets acquired with state-of-the-art instrumentation often include thousands of mass spectra, each of which comprise thousands of mass channels, and therefore mass spectrometry imaging outputs regularly amount to gigabytes of data and it is essential to develop automated software to analyse the huge spectral data rapidly and efficiently 26,27 with specific methods adapted to process such an amount of data. [28][29][30][31] For imaging mass spectrometry, the available software is limited to proprietary software developed by the equipment manufacturers and linked to specific equipment (flexImaging from Bruker Daltonics, TissueView from AB Sciex, SurfaceLab from IonTof), and to very few free-of-charge software, such as BioMap or MITICS.…”