PSII-19 Analysis of Vitamin A and E in Biological Samples After Prolonged Processing

Abstract

Abstract The objective of this study was to assess vitamin A and E concentrations in liver and serum samples after extended transport to a diagnostic laboratory. This study was designed to quantify any vitamin A and E concentrations in liver or serum after samples were stored in a Styrofoam cooler with four ice packs for up to 2 days to simulate mailing samples to a diagnostic laboratory. Liver (entire right medial lobe, divided into three equal pieces) and blood (30 mL total, into three 10 mL serum tubes; BD Vacutainer, Franklin Lankes, NJ) samples were collected from six barrows (approximately 10 kg) post-euthanasia. All the samples (liver and serum) for two pigs were placed in one Styrofoam cooler with four ice packs (ThermoSafe PolarPack; 13.97 X 15.24 cm; Sonoco; Hartsville, SC, US) which was then placed onto a benchtop (room temperature, approximately 20°C) for the duration of the study. At the designated timepoints of 0, 1, or 2 days after collection, one sample of both tissue and serum were removed from the cooler, processed, and stored at -80°C until submission to the diagnostic laboratory. To process the samples, the blood was centrifuged (2,000 x g, 10 minutes, at 4°C) and the serum was isolated and placed into 1.5 ml microcentrifuge tubes (Fisher Scientific, Waltham, MA, CAT: 05-408-129). The liver was stored in whirl pack bags (15.24 cm X 22.86 cm). Samples were analyzed for vitamin A (retinol) and E (alpha-tocopherol) concentrations at the Iowa State University Veterinarian Diagnostic Laboratory (Ames, IA). Data were analyzed using the GLIMMIX procedure in SAS 9.4 (Statistical Analysis System, Cary, NC) with animal as the experimental unit and a fixed effect of time. No differences (P > 0.05) were found in serum vitamin A and E (Table 1; vitamin A: d 0 0.26 ppm, d 1 0.26 ppm, and d 2 0.27 ppm, vitamin E: d 0 2.20 ppm, d 1 2.36 ppm, and d 2 2.28) regardless of the sample being processed the day of, one day after, or two days after being collected from the pig. There were no differences (P > 0.05) in vitamin A or E concentrations (Table 1; vitamin A: d 0 12 ppm, d 1 11 ppm, and d 2 12 ppm, vitamin E: d 0 1.74 ppm, d1 2.32 ppm, and d 2 2.08) in the liver throughout the study. Based on these data, vitamin A and E concentrations in liver and serum samples are stable for up to 2 days after being stored in a cooler with ice packs at room temperature.