Shuichi Shimma

Imaging mass spectrometry is becoming a popular visualization technique in the medical and biological sciences. For its continued development, the ability to both visualize and identify molecules directly on the tissue surface using tandem mass spectrometry (MSn) is essential. We established an imaging system based on a matrix-assisted laser/desorption ionization quadrupole ion trap time-of-flight type instrument (AXIMA-QIT, Shimadzu, Kyoto, Japan), which was compatible with both imaging and hig

A new miniature multiturn time-of-flight (TOF) analyzer "MULTUM-S II" has been designed and constructed. This instrument consists of an electron ionization source, the multiturn TOF ion optics, a detector, vacuum system, and electronic circuits. The multiturn TOF analyzer consists of four electrostatic toroidal sectors and two additional electric toroidal sectors for the purpose of ion injection/ejection. The size and weight of the system is less than 50 cm × 57 cm × 30 cm and 35 kg (including v

Visualizing tissue distribution of steroid hormones is a promising application of MALDI mass spectrometry imaging (MSI). On-tissue chemical derivatization using Girard's T reagent has enhanced the ionization efficiency of steroids. However, discriminating between structural isomers with distinct bioactivities remains a challenge. Herein, we used ion trap MS/tandem MS (MS³) to distinguish a mineralcorticoid aldosterone (Aldo) and a glucocorticoid cortisol (F), from their structural iso

Mass spectrometry (MS) was used to measure the concentrations of drug and biological compounds in plasma and tissues. Matrix-assisted laser desorption/ionization (MALDI) imaging MS (IMS) has recently been applied to the analysis of localized drugs on biological tissue surfaces. In MALDI-IMS, matrix application process is crucial for successful results. However, it is difficult to obtain homogeneous matrix crystals on the tissue surface due to endogenous salts and tissue surface heterogeneity. Co

Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) can be used to visualize the distribution of biomolecules (proteins, peptides, metabolites) and drugs on tissue surfaces. In MALDI-IMS, sample preparation is crucial for successful results. A variety of conditions, such as tissue sampling methods, tissue thickness and matrix application procedure can have an impact on the results. In this review, we summarize each sample preparation step in an orderly sequence wi

Abstract Mass spectrometry on 2D samples is known as imaging mass spectrometry , which enables us to visualize molecular distribution on a tissue surface. This technology has been developed using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometers (MALDI‐TOFMS). However, it is difficult to determine constituents of interested regions on the tissue sections. We developed the methodology to overcome this problem. We designated it on‐tissue digestion. It is performed with

Proteomics data obtained by mass spectrometry are now being combined with spatial information. This report outlines a digestion procedure for tissue sections on polyvinylidenfluoride membrane and results of a direct tandem mass spectrometry of mouse brain sections in situ. We succeeded in sequencing the digested peptides such as myelin basic protein, histon H2A, and tubulin β4 directly from tissue sections and transferred membrane. Protein blotting method can provide protein denaturation during

Imaging mass spectrometry (imaging MS) of tissue sections has become one of the main subjects in surface analysis. However, it is not easy to identify the molecular species present in imaged signals. We successfully performed imaging MS and tandem mass spectrometry (MSn) on the tissue section using a matrix-assisted laser desorption/ionization quadrupole-ion-trap time-of-flight mass spectrometer. We called the method “mass microscopy,” which is a combination of high spatial resolution imaging MS

Plants contain many secondary metabolites, which are sometimes used as spices and herbal medicines. However, the three-dimensional distribution of metabolites is usually unknown. In this study, the spatial distribution of curcumin, one of the main components of dried turmeric root, was examined. Because dried turmeric samples are extremely hard and impossible to section with existing cryomicrotomes, we introduced a new sectioning method and analyzed the two-dimensional distribution of curcumin i

Enzyme histochemistry facilitates enzyme activity visualization <i>in situ</i>; however, as it is a color-based method, molecular quantification is prohibitive. This study aimed to develop a semiquantitative, mass spectrometry imaging (MSI)-based enzyme histochemistry method to determine endogenous cholinesterase (ChE) activity. Using deuterium-labeled acetylcholine (ACh-d9) as a substrate to distinguish ACh-d9 and choline-d9 from endogenous acetylcholine and choline, respectively, the heterogen

Direct tissue analysis using a novel tandem time-of-flight (TOF-TOF) mass spectrometer is described. This system consists of a matrix-assisted laser desorption/ionization ion source, a spiral ion trajectory TOF mass spectrometer "SpiralTOF (STOF)", a collision cell, and an offset parabolic reflectron (RTOF). The features of this system are high precursor ion selectivity due to a 17-m flight path length in STOF and elimination of post-source decay (PSD) ions. The acceleration energy is 20 keV, so

Imaging mass spectrometry is a novel visualization method for a spatial distribution of biomolecules. This technology is regarded as a next generation mass spectrometry. Therefore many institutes study with several approaches and report on this new technology. We review the recent progress of imaging mass spectrometry presented at the 52nd ASMS conference 2004, and propose a new technology mass-microscope emerging from high resolution imaging mass spectrometry.