Effect of Prolonged Serum Storage Time and Varied Temperatures on Biochemical Values in African Savanna Elephants (Loxodonta africana)

Abstract

Blood samples are routinely collected from wild populations in remote locations with limited electricity, minimal diagnostic capabilities, and extreme environmental conditions. Under these conditions, serum samples may be stored for prolonged time under varied temperatures prior to processing, which could affect the ability to interpretation the results. This study’s objective was to evaluate the effects of delayed processing of serum samples and varied storage temperatures on biochemical values in African savanna elephants (Loxodonta africana). Blood samples were collected from six elephants managed by the North Carolina Zoo. For each elephant, seven red top tubes were collected. One serum sample for each elephant was analyzed on Day 0 (control group). The remaining samples were stored under different temperatures including room temperature (23 °C), refrigeration (2.2 °C), and incubation (32.2 °C), with samples from each temperature group being analyzed on Day 5 and Day 10. Many of analytes (10 out of 18) did not change significantly regardless of storage temperature or time. Refrigeration improved stability in an additional four analytes over prolonged storage. We conclude that if serum is properly separated shortly after collection, many serum biochemical analytes can be accurately measured even after suboptimal serum storage, but refrigeration and prompt evaluation are still required for some analytes.