MALDI imaging

Note The term imaging mass spectrometry (IMS) is correlated to the same acronym as ion mobility spectrometry (IMS, Chap. 4.9.2), thus one must be aware of the context in which IMS is being used. 

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Groseclose MR, Massion PP, Chaurand P, et al. High-throughput proteomic analysis of formalin-fixed paraffin-embedded tissue microarrays using MALDI imaging mass spectrometry. Proteomics 2008 8 3715-3724. 

Lemaire R, Desmons A, Tabet JC, et al. Direct analysis and MALDI imaging of formalin-fixed, paraffin-embedded tissue sections. J. Proteome Res. 2007 6 1295-1305. 

Stauber J, Lemaire R, Franck J, et al. MALDI imaging of formalin-fixed paraffin-embedded tissues application to model animals of Parkinson disease for biomarker hunting. J. Proteome Res. 2008 7 969-978. 

Matrix-Coating Method for Assisted MALDI Imaging... 

The second method of sample preparation for IMS is a matrix-coating method for MALDI imaging. In this chapter, we review the choices of matrix compound and solvent composition appropriate for IMS of tissue sections. Three kinds of matrix-application methods and examples of their use are illustrated. 

Lemaire R,Tabet J, Ducoroy P, et al. Solid ionic matrixes for direct tissue analysis and MALDI imaging. Anal. Chem. 2006 78 809-819. 

In a separate study, a protocol for Matrix-assisted laser desorption-ionization (MALDI) imaging mass spectrometry (IMS) has been proposed.18 This IMS technique provides a new approach to visualize spatial distribution of thousands of molecular species, including peptides, proteins, and their metabolites in two- or three-dimensional levels. This approach may also provide a straightforward method of determining the tissue distribution of multiple peptides or proteins in a quantitative manner.18 Chu et al.19 reported a nondestructive molecular extraction method to obtain proteins from a single FFPE or frozen tissue section, without destroying the tissue morphology, such... 

D. S. Cornett, M. L. Reyzer, P. Chaurand, and R. M. Caprioli. MALDI Imaging Mass Spectrometry Molecular Snapshots of Biochemical Systems. Nat. Meth., 4(2007) 828-833. 

MALDI IMAGING MASS SPECTROMETRY FOR DIRECT TISSUE ANALYSIS... 

MALDI imaging resolution is governed by both crystal size and laser diameter. Smaller crystal sizes provide an opportunity for better imaging resolution. With crystal diameters smaller than the laser beam, typically 50-200 im depending on the instmment, imaging resolution is generally limited to the laser diameter (Schwartz et al., 2003). 

Hsieh, Y., Chen, J., and Korfmacher, W. A. (2007). Mapping pharmaceuticals in tissues using MALDI imaging mass spectrometry. J. Pharmacol. Toxicol. Methods 55 193-200. 

The sample preparation procedures for the direct analysis of small molecules in tissue have been described by several papers [120-124], Tissues (brain, heart, lung, kidney, liver, etc.), were immediately frozen and stored at -80 °C after harvest. The frozen tissues were subsequently cut into serial 10-20 pm thick section which was typically prepared by cryosectioning on a microtome at a temperature of -20 °C. The adjacent sections were gently mounted onto a conductive surface, MALDI imaging target plate or glass slides. These plates were desiccated under low vacuum for a short period of time until dry, then robotically or manually coated with the... 

Bouslimani [153] studied oxaliplatin in rat kidney. Frozen kidney tissue sections of 15 pm thickness were coated using 10 mg/mL CHCA in ACN-0.1%TFA (50 50, vol/vol) either manually or using an Airbrush sprayer. The MALDI imaging was performed using a MALDI-TOF/TOF analyzer. Oxaliplatin in kidney tissues was detected after incubation under HIPEC conditions. This experiment confirmed that oxaliplatin and its metabolites, monocysteine and monomethionine complexes were located at the cortex with weak penetration inside kidney (0.2-0.5 mm). 

Cornett D, Reyzer M, Chaurand P, Caprioli R (2007) MALDI imaging mass spectrometry molecular snapshots of biochemical systems. Nat Methods 10 828-833. doi 10.1038/ nmethl094... 

Grey A, Chaurand P, Caprioli R, Schey K (2009) MALDI imaging mass spectrometry of integral membrane protein from ocular lens and retinal tissue. J Proteome Res 8 3278-3283. 

Rauser S, Marquardt C, Balluff B, Deininger S, Albers C, Belau E, Hartmer R, Suckau D, Specht K, Ebert M, Schmitt M, Aubele M, Hofler H, Walch A (2010) Classification of HER2 receptor status in breast cancer tissue by MALDI imaging mass spectrometry. J Proteome Res 9 1854-1863. doi 10.1021/pr901008d... 

Wang H, Post S, Woods A (2008) A minimalist approach to MALDI imaging of glycerophospholipids and sphingolipids in rat brain sections. Int J Mass Spectrom 278 143-149. doi 10. 1016/j.ijms.2008.04.005... 

Chen J, Hsieh Y, Knemeyer I, Crossman L, Korfmacher W (2008) Visualization of first-pass drug metabolism of terfenadine by MALDI-imaging mass spectrometry. Drug Metab Lett 2 1-4... 

Schwamborn K, Krieg R, Reska M, Jakse G, Knuechel R, Wellmann A (2007) Identifying prostate carcinoma by MALDI-imaging. Int J Mol Med 20 155-159... 

Puolitaival S, Bumum K, Cornett D, Caprioli R (2008) Solvent-free matrix dry-coating for MALDI imaging of phospholipids. J Am Soc Mass Spectrom 19 882-886. doi 10.1016/j. jasms.2008.02.013... 

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