title: Stability studies of ubiquinol in plasma.
abstract: BACKGROUND
  Ubiquinol is a sensitive redox marker in the first line of the antioxidative defence mechanism and is increasingly being measured in oxidation studies. Because of its apparent instability during storage and processing, we compared various storage conditions.
  
  
  METHODS
  Blood was collected from three volunteers into tubes containing EDTA; it was then separated at 4 degrees C and cryopreserved with saccharose (final concentration 6 g/L). Aliquots were stored with or without glutathione or butylated hydroxytoluene at -20 degrees C and -80 degrees C.
  
  
  CONCLUSIONS
  Ubiquinol in samples stored at -20 degrees C was not stable; however, it was stable when stored at -80 degrees C, even without addition of antioxidant. By contrast, alpha-tocopherol was stable under all conditions studied.
authors.affiliation: Laboratory of General Internal Medicine, 564 AKC, University Medical Center, Nijmegen, 6500 HB Nijmegen, The Netherlands.
authors.forename: M P C
authors.initials: MP
authors.lastname: Hectors
authors.forename: L J H
authors.initials: LJ
authors.lastname: van Tits
authors.forename: Y B
authors.initials: YB
authors.lastname: de Rijke
authors.forename: P N M
authors.initials: PN
authors.lastname: Demacker
mesh_terms: D002624:Chemistry, Clinical / Q000379:methods*; D004492:Edetic Acid / Q000494:pharmacology; D005819:Genetic Markers; D006801:Humans; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D013048:Specimen Handling; D013696:Temperature; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000097:blood* / Q000378:metabolism; D024502:alpha-Tocopherol / Q000097:blood
chemical_list: D005819:Genetic Markers; D014451:Ubiquinone; D004492:Edetic Acid; D024502:alpha-Tocopherol; C003741:ubiquinol