Direct Acquisition of Matrix-assisted Laser Desorption/Ionization Time-of-Flight Mass Spectra from Laser Capture Microdissected Tissues

Abstract

Recent studies have demonstrated the usefulness of laser capture microdissection (LCM) in gene expression studies of pure cell populations derived from healthy and diseased tissues (1)(2)(3). However, mRNA expression does not necessarily correlate with protein abundance or predict posttranslational modifications (4). Currently, a few groups have reported details of protein expression profiling of cells captured by LCM, using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) followed by peptide mass fingerprinting of selected proteins (5)(6). Although such an approach represents the gold standard for global analysis of protein expression, 2D-PAGE often is impractical for diagnostic applications. We describe a rapid and sensitive method to obtain an abridged protein expression profile from microdissected cells by the direct acquisition of matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectra from LCM transfer films.