title: Preanalytic influence of sample handling on SELDI-TOF serum protein profiles.
abstract: BACKGROUND
  High-throughput proteomic methods for disease biomarker discovery in human serum are promising, but concerns exist regarding reproducibility of results and variability introduced by sample handling. This study investigated the influence of different preanalytic handling methods on surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) protein profiles of prefractionated serum. We investigated whether older collections with longer sample transit times yield useful protein profiles, and sought to establish the most feasible collection methods for future clinical proteomic studies.
  
  
  METHODS
  To examine the effect of tube type, clotting time, transport/incubation time, temperature, and storage method on protein profiles, we used 6 different handling methods to collect sera from 25 healthy volunteers. We used a high-throughput, prefractionation strategy to generate anion-exchange fractions and examined their protein profiles on CM10, IMAC30-Cu, and H50 arrays by using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry.
  
  
  RESULTS
  Prolonged transport and incubation at room temperature generated low mass peaks, resulting in distinctions among the protocols. The most and least stringent methods gave the lowest overall peak variances, indicating that proteolysis in the latter may have been nearly complete. For samples transported on ice there was little effect of clotting time, storage method, or transit time. Certain proteins (TTR, ApoCI, and transferrin) were unaffected by handling, but others (ITIH4 and hemoglobin beta) displayed significant variability.
  
  
  CONCLUSIONS
  Changes in preanalytical handling variables affect profiles of serum proteins, including proposed disease biomarkers. Proteomic analysis of samples from serum banks collected using less stringent protocols is applicable if all samples are handled identically.
authors.affiliation: Translational Research Laboratory, Institute of Women's Health, University College London, London, United Kingdom. jtimms@ludwig.ucl.ac.uk
authors.forename: John F
authors.initials: JF
authors.lastname: Timms
authors.forename: Elif
authors.initials: E
authors.lastname: Arslan-Low
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Gentry-Maharaj
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Luo
authors.forename: Davy
authors.initials: D
authors.lastname: T'Jampens
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Podust
authors.forename: Jeremy
authors.initials: J
authors.lastname: Ford
authors.forename: Eric T
authors.initials: ET
authors.lastname: Fung
authors.forename: Alex
authors.initials: A
authors.lastname: Gammerman
authors.forename: Ian
authors.initials: I
authors.lastname: Jacobs
authors.forename: Usha
authors.initials: U
authors.lastname: Menon
mesh_terms: D001798:Blood Proteins / Q000032:analysis*; D001800:Blood Specimen Collection / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D017698:Postmenopause; D040901:Proteomics; D016032:Randomized Controlled Trials as Topic; D044967:Serum; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001798:Blood Proteins