Related Experiment Videos
Stability of gamma-glutamyltransferase activity in calf sera after refrigerated or frozen storage
F Muller1, J W Tyler, S M Parish
1Department of Veterinary Clinical Sciences, Washington State University, Pullman 99164, USA.
Objectives:
To examine stability of -glutamyltransferase (GGT) activity in stored serum from neonatal calves.
Animals:
10 commercial beef calves between 36 and 60 hours old.
Procedure:
Serum samples were obtained from the calves, and each sample was divided into 8 aliquots. Serum GGT activity was measured on day 0 (fresh) and days 1, 2, 3, and 4 of refrigerated storage (4 C) and weeks 1, 2, and 3 of frozen storage (-20 C).
Results:
Serum GGT activities for each of the refrigerated aliquots did not significantly differ from day zero, with serum GGT activity (expressed as a percentage of initial activity) > 99% on all 4 days. Serum GGT activity in frozen aliquots decreased significantly after 1 and 2 weeks of frozen storage, 97 and 98%, respectively; however, this decrease in GGT activity was not biologically significant. The observed GGT activity did not decrease significantly in the samples stored frozen for 3 weeks; these samples retained 99% of initial activity.
Conclusion:
The observed stability of serum GGT activity indicates that serum may be obtained, stored, and batch processed at a later time. This stability during storage is important to the success of a bovine passive transfer monitoring program based on GGT activity.