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This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: M700137-MCP200v1 7/1/193    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Glossary Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Winkler, W. Articles by Oehler, R. Search for Related Content PubMed PubMed Citation Articles by Winkler, W. Articles by Oehler, R. Social Bookmarking                      What's this?

Molecular & Cellular Proteomics 7:193-203, 2008.
© 2008 by The American Society for Biochemistry and Molecular Biology, Inc.

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Research

Biological Variation of the Platelet Proteome in the Elderly Population and Its Implication for Biomarker Research^*,S

Wolfgang Winkler^,, Maria Zellner^,¶, Michael Diestinger^¶, Rita Babeluk^¶, Martina Marchetti, Alexandra Goll^||, Sonja Zehetmayer^||, Peter Bauer^||, Eduard Rappold^**, Ingrid Miller, Erich Roth^¶, Günter Allmaier and Rudolf Oehler^¶,

From the Institute of Chemical Technologies and Analytics, Vienna University of Technology, A-1060 Vienna, Austria, ^¶ Department of Surgery and ^|| Section of Medical Statistics, Medical University of Vienna, A-1090 Vienna, Austria, ^** Geriatric centre of the Otto Wagner Hospital, A-1140 Vienna, Austria, and Institute of Medical Chemistry, Department of Natural Sciences, University of Veterinary Medicine, A-1210 Vienna, Austria

Knowledge about the extent of total variation experienced between samples from different individuals is of great importance for the design of not only proteomics but every clinical study. This variation defines the smallest statistically significant detectable signal difference when comparing two groups of individuals. We isolated platelets from 20 healthy human volunteers aged 56–100 years because this age group is most commonly encountered in the clinics. We determined the technical and total variation experienced in a proteome analysis using two-dimensional DIGE with IPGs in the pI ranges 4–7 and 6–9. Only spots that were reproducibly detectable in at least 90% of all gels (n = 908) were included in the study. All spots had a similar technical variation with a median coefficient of variation (cv) of about 7%. In contrast, spots showed a more diverse total variation between individuals with a surprisingly low median cv of only 18%. Because most known biomarkers show an effect size in a 1–2-fold range of their cv, any future clinical proteomics study with platelets will require an analytical method that is able to detect such small quantitative differences. In addition, we calculated the minimal number of samples (sample size) needed to detect given protein expression differences with statistical significance.

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