title: Compressed matrix thin film (CMTF)-assisted laser desorption ionization mass spectrometric analysis.
abstract: The inhomogeneous re-crystallization process of matrix materials is the major concerns associated with matrix assisted laser desorption/ionization (MALDI) analysis. We describe here the approach termed compressed matrix thin film (CMTF) in order to make a uniform matrix deposition. In this approach, solid matrix particles are compressed under 10 MPa of pressure by a compressor that is regularly used in infrared spectroscopic analysis. Then aqueous samples can be deposited on the surface of the matrix film. Major advantages of the CMTF approach are summarized as follows. (1) Reproducible sample preparation procedure. Size and thickness of matrix thin films can be controlled by using a fixed mold.force and known amount of matrix materials. (2) Significantly decreased shot-to-shot variations and enhanced reproducibility. (3) Tolerance for in situ salt washing. Because matrix materials are hydrophobic, salts can be washed away while proteins or peptides are retained on the surface of matrix thin films through hydrophobic interactions. (4) Improved sensitivity. The hydrophobic coating of MALDI sample plate by matrix thin films prevents the spreading of samples across the plate and confines analytes to a small area, leading to increased local concentration. (5) A new means for tissue analysis. Tissue sections can be directly transferred to the uniform surface of matrix materials for reproducible and quantitative comparison of different molecules in different localization. The proposed CMTF should be an enabling technique for mass spectrometric analysis with improved correlations between signal intensities and sample quantities.
authors.affiliation: Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei, PR China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Huang
authors.forename: Xiao
authors.initials: X
authors.lastname: Xiao
authors.forename: Yinping
authors.initials: Y
authors.lastname: Xie
authors.forename: Hubert
authors.initials: H
authors.lastname: Kageruka
authors.forename: Youe
authors.initials: Y
authors.lastname: Zhou
authors.forename: Fengjiao
authors.initials: F
authors.lastname: Deng
authors.forename: Hongying
authors.initials: H
authors.lastname: Zhong
mesh_terms: D000818:Animals; D019245:Compressive Strength; D003373:Coumaric Acids / Q000032:analysis*; D005841:Gentisates / Q000032:analysis*; D057927:Hydrophobic and Hydrophilic Interactions; D051381:Rats; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods* / Q000592:standards
chemical_list: D003373:Coumaric Acids; D005841:Gentisates; C007175:alpha-cyano-4-hydroxycinnamate; C010925:2,5-dihydroxybenzoic acid