Effect of repeated freeze-thaw cycles on routine plasma biochemical constituents in canine plasma.
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.
Reynolds
Brice
B
UMR 181 de Physiopathologie et Département des Sciences Cliniques, Ecole Nationale Vétérinaire de Toulouse, Toulouse, France.
Taillade
Benjamin
B
Médaille
Christine
C
Palenché
Florence
F
Trumel
Cathy
C
Lefebvre
Hervé Pierre
HP
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
D001786:Blood Glucose; D001798:Blood Proteins; D008903:Minerals; D014508:Urea; D003404:Creatinine; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D003402:Creatine Kinase; D000469:Alkaline Phosphatase