On-chip microextraction for proteomic sample preparation of in-gel digests

Research output: Contribution to journalArticle

Abstract

Despite the high sensitivity and relatively high tolerance for contaminants of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) there is often a need to purify and concentrate the sample solution, especially after in-gel digestion of proteins separated by two-dimensional gel electrophoresis (2-DE). A silicon microextraction chip (SMEC) for sample clean-up and trace enrichment of peptides was manufactured and investigated. The microchip structure was used to trap reversed-phase chromatography media (POROS R2 beads) that facilitates sample purification/enrichment of contaminated and dilute samples prior to the MALDI-TOF MS analysis. The validity of the SMEC sample preparation technique was successfully investigated by performing analysis on a 10 nM peptide mixture containing 2 m urea in 0.1 m phosphate-buffered saline with MALDI-TOF MS. It is demonstrated that the microchip sample clean-up and enrichment of peptides can facilitate identification of proteins from 2-DE separations. The microchip structure was also used to trap beads immobilized with trypsin, thereby effectively becoming a microreactor for enzymatic digestion of proteins. This microreactor was used to generate a peptide map from a 100 nM bovine serum albumin sample.

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Authors
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Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Basic Medicine

Keywords

  • Electrophoresis, Gel, Two-Dimensional, Enzymes, Immobilized, Peptides, Protein Array Analysis, Proteome, Reproducibility of Results, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Evaluation Studies, Journal Article, Research Support, Non-U.S. Gov't
Original languageEnglish
Pages (from-to)413-421
Number of pages9
JournalProteomics
Volume2
Issue number4
Publication statusPublished - 2002 Apr
Publication categoryResearch
Peer-reviewedYes