title: LacaScore: a novel plasma sample quality control tool based on ascorbic acid and lactic acid levels.
abstract: BACKGROUND
  Metabolome analysis is complicated by the continuous dynamic changes of metabolites in vivo and ex vivo. One of the main challenges in metabolomics is the robustness and reproducibility of results, partially driven by pre-analytical variations.
  
  
  OBJECTIVE
  The objective of this study was to analyse the impact of pre-centrifugation time and temperature, and to determine a quality control marker in plasma samples.
  
  
  METHODS
  Plasma metabolites were measured by gas chromatography-mass spectrometry (GC-MS) and analysed with the MetaboliteDetector software. The metabolites, which were the most labile to pre-analytical variations, were further measured by enzymatic assays. A score was calculated for their use as quality control markers.
  
  
  RESULTS
  The pre-centrifugation temperature was shown to be critical in the stability of plasma samples and had a significant impact on metabolite concentration profiles. In contrast, pre-centrifugation delay had only a minor impact. Based on the results of this study, whole blood should be kept on wet ice and centrifuged within maximum 3 h as a prerequisite for preparing EDTA plasma samples fit for the purpose of metabolome analysis.
  
  
  CONCLUSIONS
  We have established a novel blood sample quality control marker, the LacaScore, based on the ascorbic acid to lactic acid ratio in plasma, which can be used as an indicator of the blood pre-centrifugation conditions, and hence the suitability of the sample for metabolome analyses. This method can be applied in research institutes and biobanks, enabling assessment of the quality of their plasma sample collections.
authors.affiliation: Integrated Biobank of Luxembourg, 6 rue Ernest Barble, 1210 Luxembourg, Luxembourg ; Luxembourg Centre for Systems Biomedicine, 7, Avenue des Hauts-Fourneaux, 4362 Esch-Belval, Luxembourg.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Trezzi
authors.affiliation: Sérothèque Centrale, Département de Médecine Génétique et de Laboratoire, Hôpitaux Universitaires de Geneve, 1211 Geneve 14, Switzerland ; International Society for Biological and Environmental Repositories (ISBER) Biospecimen Science Working Group, Vancouver, Canada.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Bulla
authors.affiliation: Integrated Biobank of Luxembourg, 6 rue Ernest Barble, 1210 Luxembourg, Luxembourg.
authors.forename: Camille
authors.initials: C
authors.lastname: Bellora
authors.affiliation: Institute of Clinical Chemistry and Laboratory Diagnostics and Integrierte BioBank Jena (IBBJ), Jena University Hospital, Erlanger Allee 101, 07740 Jena, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Rose
authors.affiliation: Sérothèque Centrale, Département de Médecine Génétique et de Laboratoire, Hôpitaux Universitaires de Geneve, 1211 Geneve 14, Switzerland.
authors.forename: Pierre
authors.initials: P
authors.lastname: Lescuyer
authors.affiliation: Institute of Clinical Chemistry and Laboratory Diagnostics and Integrierte BioBank Jena (IBBJ), Jena University Hospital, Erlanger Allee 101, 07740 Jena, Germany ; International Society for Biological and Environmental Repositories (ISBER) Biospecimen Science Working Group, Vancouver, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Kiehntopf
authors.affiliation: Luxembourg Centre for Systems Biomedicine, 7, Avenue des Hauts-Fourneaux, 4362 Esch-Belval, Luxembourg.
authors.forename: Karsten
authors.initials: K
authors.lastname: Hiller
authors.affiliation: Integrated Biobank of Luxembourg, 6 rue Ernest Barble, 1210 Luxembourg, Luxembourg ; International Society for Biological and Environmental Repositories (ISBER) Biospecimen Science Working Group, Vancouver, Canada.
authors.forename: Fay
authors.initials: F
authors.lastname: Betsou
keywords: Biobank; GC/MS; Metabolomics; Plasma processing; Pre-analytics; Quality control