Novel Microscope Enables Direct Mass Spectrometry Analysis

A unique imaging mass microscope has been developed as a new research tool that offers mass spectrometric analysis capability in a single instrument and resolution enabling the visualization of the sub-cellular distribution of molecules.

The positional information of molecules is lost in traditional mass spectrometric analysis. Shimadzu Corporation (Kyoto, Japan) introduces the “iMScope” imaging mass microscope, a new hybrid type of microscope that combines both an optical microscope and an atmospheric pressure ionization mass spectrometer. The optical microscope allows the observation of high-resolution morphological images, and the hybrid ion trap time of flight mass spectrometer allows both identification and visualization of the distribution of specific molecules in the sectioned sample of interest. In addition, the relative abundance of specific molecules (such as drugs and their metabolites) localized in different tissues can be resolved and compared. The dedicated software for the iMScope, “Imaging MS Solution,” can set all operational parameters for viewing optical microscope images, and many sets of operation parameters are available as default method files; hence, users can perform the imaging mass spectrometry without troublesome additional settings.

Proprietary ultrafocusing laser optics and the highly reproducible, high precision 3D automated sample transfer stage result in a superior spatial mass spectrometry resolution of 5 µm—finest spatial resolution in imaging mass spectrometry, using matrix assisted laser desorption ionization (MALDI-TOF) mass spectrometer, commercially available. The iMScope is capable of analyzing living cells or tissue samples by atmosphere MALDI. By superimposing the two images obtained based on these different principles, the team of scientists from Shimadzu, Hamamatsu University of Medicine, and Keio University have created this powerful new research tool.

The iMScope expands potential research opportunities to a diversity of fields, including direct analyses of biological samples as well as of manufactured devices. Potential biological applications include disease biomarker research and functional biology research, such as for development of early stage cancer indicators with biomarkers in cancer tissue; for analysis of micro tissue (smaller than 10 µm; e.g., pigment layer of the retina); as a new pharmacokinetics tool monitoring drug metabolism; and for advancing agricultural and horticultural products via locating the distribution of key compounds. The iMScope is also well suited for various industrial applications, particularly for defect analysis of electronic components and synthetic polymer materials.

In addition to enabling direct analysis of optical microscope samples, the use of atmosphere MALDI, compared to vacuum MALDI, enables analysis of volatile molecules and biological tissues closer living conditions, as well as shorter instrument start-up time. Additionally, the high speed Nd:YAG laser can ionize molecules at 1 kHz, and original ion optics can acquire the ions (which are ionized by several laser shots) and analyze those at once, as this novel technology provides about 100 times faster high-speed imaging mass spectrometry than conventional mass spectrometers. Hence, the ultra-fast performance of the iMScope also accelerates research progress.

The iMScope will be presented at both KSBMB 2013, Korean Society of Biochemistry and Molecular Biology (May 14-16, 2013) and ASMS 2013, American Society of Mass Spectrometry (June 9-13, 2013, in Minneapolis, MN, USA), in conjunction with the new iMLayer, matrix sample preparation device for tissue imaging.

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Shimadzu
iMScope