title: Effect of repeated freeze-thaw cycles on routine plasma biochemical constituents in canine plasma.
abstract: BACKGROUND
  The effect of repeated freeze-thaw cycles on plasma constituents has not been assessed in dogs, although such a procedure is not uncommon to use in routine laboratory practice.
  
  
  OBJECTIVE
  To assess the effect of freeze-thaw cycles on routine plasma constituents in healthy dogs.
  
  
  METHODS
  Six healthy adult dogs were used. Blood was sampled and placed in heparinized tubes. After centrifugation, plasma was separated into 5 aliquots. One aliquot was considered as the reference aliquot and used immediately for the assay of all of the biochemical constituents. All of the other aliquots were stored at 20 degrees C. Three aliquots underwent 1, 2, or 3 freeze-thaw cycles during a 1- to 3-day period. The last aliquot remained at 20 degrees C throughout the study and was thawed on the third day. The following biochemical constituents were assayed: glucose, urea, creatinine, total proteins, sodium, potassium, chloride, calcium, phosphates, aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK), and alkaline phosphatase (ALP).
  
  
  RESULTS
  No clinically relevant change was observed between the different aliquots for all of the constituents.
  
  
  CONCLUSIONS
  Repeated freeze-thaw cycles do not cause changes in the biochemical constituents studied in canine plasma.
authors.affiliation: UMR 181 de Physiopathologie et Département des Sciences Cliniques, Ecole Nationale Vétérinaire de Toulouse, Toulouse, France.
authors.forename: Brice
authors.initials: B
authors.lastname: Reynolds
authors.forename: Benjamin
authors.initials: B
authors.lastname: Taillade
authors.forename: Christine
authors.initials: C
authors.lastname: Médaille
authors.forename: Florence
authors.initials: F
authors.lastname: Palenché
authors.forename: Cathy
authors.initials: C
authors.lastname: Trumel
authors.forename: Hervé Pierre
authors.initials: HP
authors.lastname: Lefebvre
mesh_terms: D000410:Alanine Transaminase / Q000032:analysis; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D001219:Aspartate Aminotransferases / Q000032:analysis; D001774:Blood Chemical Analysis / Q000379:methods / Q000662:veterinary; D001786:Blood Glucose / Q000032:analysis; D001793:Blood Preservation / Q000379:methods / Q000592:standards / Q000662:veterinary*; D001798:Blood Proteins / Q000032:analysis; D001800:Blood Specimen Collection / Q000379:methods / Q000662:veterinary; D003402:Creatine Kinase / Q000032:analysis; D003404:Creatinine / Q000032:analysis; D004285:Dogs / Q000097:blood*; D005615:Freezing; D008903:Minerals / Q000032:analysis; D010949:Plasma / Q000737:chemistry* / Q000201:enzymology*; D015203:Reproducibility of Results; D013696:Temperature; D013997:Time Factors; D014508:Urea / Q000032:analysis
chemical_list: D001786:Blood Glucose; D001798:Blood Proteins; D008903:Minerals; D014508:Urea; D003404:Creatinine; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D003402:Creatine Kinase; D000469:Alkaline Phosphatase