Microscale sample deposition onto hydrophobic target plates for trace level detection of neuropeptides in brain tissue by MALDI-MS
Wei, Hui; Dean, Stacey L.; Parkin, Mark C.; Nolkrantz, Kerstin; O'Callaghan, James P.; Kennedy, Robert T.
2005-10
Citation
Wei, Hui; Dean, Stacey L.; Parkin, Mark C.; Nolkrantz, Kerstin; O'Callaghan, James P.; Kennedy, Robert T. (2005)."Microscale sample deposition onto hydrophobic target plates for trace level detection of neuropeptides in brain tissue by MALDI-MS." Journal of Mass Spectrometry 40(10): 1338-1346. <http://hdl.handle.net/2027.42/48772>
Abstract
A sample preparation method that combines a modified target plate with a nanoscale reversed-phase column (nanocolumn) was developed for detection of neuropeptides by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A gold-coated MALDI plate was modified with an octadecanethiol (ODT) self-assembled monolayer to create a hydrophobic surface that could concentrate peptide samples into a ∼200–500-µm diameter spot. The spot sizes generated were comparable to those obtained for a substrate patterned with 200-µm hydrophilic spots on a hydrophobic substrate. The sample spots on the ODT-coated plate were 100-fold smaller than those formed on an unmodified gold plate with a 1-µl sample and generated 10 to 50 times higher mass sensitivity for peptide standards by MALDI-TOF MS. When the sample was deposited on an ODT-modified plate from a nanocolumn, the detection limit for peptides was as low as 20 pM for 5-µl samples corresponding to 80 amol deposited. This technique was used to analyze extracts of microwave-fixed tissue from rat brain striatum. Ninety-eight putative peptides were detected including several that had masses matching neuropeptides expected in this brain region such as substance P, rimorphin, and neurotensin. Twenty-three peptides had masses that matched peaks detected by capillary liquid chromatography with electrospray ionization MS. 1 2 Copyright © 2005 John Wiley & Sons, Ltd.Publisher
John Wiley & Sons, Ltd.
ISSN
1076-5174 1096-9888
Other DOIs
PMID
16217843
Types
Article
URI
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=retrieve&db=pubmed&list_uids=16217843&dopt=citationMetadata
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