title: Preanalytical mixing of whole-blood specimens in the context of the Athlete Passport.
abstract: BACKGROUND
  Full blood counts are now used as evidence that athletes have used banned blood doping. This has led to legal scrutiny of the efficacy of preanalytical procedures such as specimen homogenisation.
  
  
  OBJECTIVE
  To characterise the impact of different mixing strategies on whole-blood homogeneity.
  
  
  METHODS
  Manual inversion, mechanical mixing and automatic mixing performed by the Sysmex XT-2000i were evaluated.
  
  
  RESULTS
  Automated mixing by the instrument, or 1 min of mechanical mixing, thoroughly homogenised specimens even for tubes that had been refrigerated and left undisturbed for 36 h. Manual inversions were almost as effective, provided that specimens were first allowed to equilibrate to ambient temperatures.
  
  
  CONCLUSIONS
  Current sport guidelines that mandate at least 15 min of mechanical mixing are excessive. Except where specimens are presented to the instrument manually, mechanical mixing is redundant in the context of full blood counts.
authors: SIAB Research, Gold Coast, Queensland, Australia. heyasho@hotmail.com
authors: Michael
authors: M
authors: Ashenden
authors: Anthea
authors: A
authors: Clarke
authors: Ken
authors: K
authors: Sharpe
authors: Giuseppe
authors: G
authors: d'Onofrio
authors: Graeme
authors: G
authors: Allbon
authors: Christopher J
authors: CJ
authors: Gore
mesh_terms: D000704:Analysis of Variance; D019985:Benchmarking; D001772:Blood Cell Count / Q000592:standards; D004300:Doping in Sports; D006801:Humans; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011793:Queensland; D015203:Reproducibility of Results; D013048:Specimen Handling / Q000592:standards; D015813:Substance Abuse Detection / Q000379:methods* / Q000592:standards; D013696:Temperature; D013997:Time Factors