title: The analytic impact of a reduced centrifugation step on chemistry and immunochemistry assays: an evaluation of the Modular Pre-Analytics.
abstract: BACKGROUND
  The COBAS 6000 system can be completed by a Modular Pre-Analytics (MPA), an integrated laboratory automation system that streamlines preanalysis. For an optimal throughput, the MPA centrifuges blood collection tubes for 5 min at 1885 × g - a centrifugation time that is not in concordance with the World Health Organization guidelines which suggest centrifugation for 10/15 min at 2000-3000 × g.
  
  
  METHODS
  In this study, the analytical outcome of 50 serum and 50 plasma samples centrifuged for 5 or 10 min at 1885 × g was investigated. The study included routine chemistry and immunochemistry assays on the COBAS 6000 and the Minicap capillary electrophoresis.
  
  
  RESULTS
  Deming-fit and Bland-Altman plots of the 5-min and 10-min centrifugation steps indicated a significant correlation in serum samples. The lipaemia index in plasma samples centrifuged for 5 min displayed a statistically significant variation when compared with the 10-min centrifugation.
  
  
  CONCLUSIONS
  Preanalytical centrifugation can be successfully down-scaled to a duration of 5 min for most routine chemistry and immunochemistry assays in serum and plasma samples. To prevent inaccurate results in plasma samples with an increased lipaemia index from being reported, the laboratory information system was programmed to withhold results above certain lipaemia indices. The presented data support the use of a 5-min centrifugation step to improve turnaround times, thereby meeting one of the desires of the requesting clinicians.
authors.affiliation: Department of Clinical Chemistry & Laboratory Hematology, St Elisabeth Hospital, Hilvarenbeekseweg 60, PO Box 90151, 5000 LC, Tilburg, The Netherlands. m.koenders@elisabeth.nl
authors.forename: Mieke M J F
authors.initials: MM
authors.lastname: Koenders
authors.forename: Marco E J F
authors.initials: ME
authors.lastname: van Hurne
authors.forename: Monique
authors.initials: M
authors.lastname: Glasmacher-Van Zijl
authors.forename: Geesje
authors.initials: G
authors.lastname: van der Linde
authors.forename: Bert W J J M
authors.initials: BW
authors.lastname: Westerhuis
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods*; D001800:Blood Specimen Collection; D002498:Centrifugation; D007120:Immunochemistry / Q000379:methods*; D013997:Time Factors