The effect of pre-analytical factors on stability of the proteome and selected metabolites in cerebrospinal fluid (CSF)

Rosenling, T., Slim, C. L., Christin, C., Coulier, L., Bosman, J., Shi, S., Suits, F., Stockhofe-Zurwieden, N., Vreeken, R., Hankemeier, T., Gool, A., Luider, T. & Bischoff, R., 2009, In : J Proteome Res.. 8, p. 5511 - 5522

Research output: Contribution to journalArticleAcademicpeer-review

  • T. Rosenling
  • Christiaan Lucas Slim
  • C. Christin
  • L. Coulier
  • J Bosman
  • S. Shi
  • F. Suits
  • N. Stockhofe-Zurwieden
  • R. Vreeken
  • T Hankemeier
  • A. Gool
  • T. Luider
  • Rainer Bischoff
In order to standardize the use of cerebrospinal fluid (CSF) for biomarker research, a set of stability studies have been performed on porcine samples to investigate the influence of common sample handling procedures on proteins, peptides, metabolites and free amino acids. This study focuses at the effect on proteins and peptides, analyzed by applying label-free quantitation using microfluidics nano-scale liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (chipLC-MS) as well as matrix assisted laser desorption ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FT-ICR-MS) and Orbitrap LC-MS/MS to trypsin-digested CSF samples. The factors assessed were a 30 or 120 min time delay at room temperature before storage at -80 degrees C after the collection of CSF in order to mimic potential delays in the clinic (delayed storage), storage at 4 degrees C after trypsin digestion to mimic the time that samples remain in the cooled auto-sampler of the analyzer, and repeated freeze-thaw cycles to mimic storage and handling procedures in the laboratory. The delayed storage factor was also analyzed by gas chromatography mass spectrometry (GC-MS) and liquid chromatography mass spectrometry (LC-MS) for changes on metabolites and free amino acids, respectively. Our results show that repeated freeze/thawing introduced changes in transthyretin peptide levels. The trypsin digested samples left at 4 degrees C in the autosampler showed a time-dependent decrease of peak areas for peptides from prostaglandin D-synthase and serotransferrin. Delayed storage of CSF lead to changes in prostaglandin D-synthase derived peptides as well as to increased levels of certain amino acids and metabolites. The changes of metabolites, amino acids and proteins in the delayed storage study appear to be related to remaining white blood cells. Our recommendations are to centrifuge CSF samples immediately after collection to remove white blood cells, aliquot and then snap freeze the supernatant in liquid nitrogen for storage at -80 degrees C. Preferably samples should not be left in the autosampler for more than 24 hours and freeze/thaw cycles should be avoided if at all possible
Original languageDutch
Pages (from-to)5511 - 5522
JournalJ Proteome Res.
Publication statusPublished - 2009

ID: 1943554