Biological Variation of the Platelet Proteome in the Elderly Population and Its Implication for Biomarker Research

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