title: Analysis of reproducibility and variability from a frozen sample aliquotter by metabolomics analysis.
abstract: OBJECTIVE
  A novel frozen sample aliquotter, which consists of a drilling system in which a coring probe extracts multiple frozen cores from one frozen sample, was developed to avoid thawing and refreezing of samples. The aliquotter was tested to determine if it is suitable for metabolomics analyses in reproducibility and variability studies.
  
  
  METHODS
  Twenty volunteers (10 males and 10 females) were enrolled in this study. Each of the volunteers' serum was aliquotted to one 1.8 mL tube and one 150 μL tube (control). Then the serum was frozen at -80°C for 2 weeks. Four frozen cores were taken from the perimeter of each of the 1.8 mL parent tubes by the aliquotter. The cores, the frozen serum remaining in the parent samples after extracting four frozen cores (Remainder), and control were analyzed using a gas chromatography time-of-flight mass spectrometry platform to test the reproducibility and variability of the samples in metabolomics analyses.
  
  
  RESULTS
  There were no significant differences between the Core, Remainder, and Control groups based on multivariate analysis of metabolomics analyses. In the reproducibility study, the average CV for the cores was 10.07%. In the variability study, the average changes ranged from 81.07% to 119.82% and 81.06% to 119.74% for Core and Remainder samples compared to Control, respectively.
  
  
  CONCLUSIONS
  The frozen sample aliquotter technology can extract multiple consistently homogenous aliquots without thawing the parent sample, and the coring process with serum produces good samples for metabolomics analyses.
authors: 1 Center for Translational Medicine, Shanghai Key Laboratory of Diabetes, The Metabolic Diseases Biobank, Shanghai Jiao Tong University Affiliated Sixth People's Hospital , Shanghai, China .
authors: Yinan
authors: Y
authors: Zhang
authors: Huijuan
authors: H
authors: Lu
authors: Yixie
authors: Y
authors: Shen
authors: Ruihua
authors: R
authors: Chen
authors: Pingyan
authors: P
authors: Fang
authors: Hong
authors: H
authors: Yu
authors: Congrong
authors: C
authors: Wang
authors: Weiping
authors: W
authors: Jia
mesh_terms: D000328:Adult; D000368:Aged; D001771:Blood Banks; D015925:Cryopreservation; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D008297:Male; D055442:Metabolome; D055432:Metabolomics / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D013048:Specimen Handling / Q000295:instrumentation* / Q000379:methods