Kempf Jennifer, Melliger Roger H, Reusch Claudia E, Kook Peter H
J Am Vet Med Assoc. 2018 Jun 1;252(11):1368-1371. doi: 10.2460/javma.252.11.1368.
OBJECTIVE To evaluate the effects of storage conditions and duration on cobalamin concentration in serum samples from dogs and cats. DESIGN Experiment. SAMPLE Serum samples from 9 client-owned cats and 9 client-owned dogs. PROCEDURES Serum harvested from freshly obtained blood samples was separated into 11 aliquots/animal. One aliquot (baseline sample) was routinely transported in light-protected tubes to the laboratory for cobalamin assay; each of the remaining aliquots was stored in a refrigerator (6°C; n = 5) or at room temperature (20°C) with exposure to daylight (5) for 24, 48, 72, 96, or 120 hours. Aliquots were subsequently wrapped in aluminum foil, frozen (-20°C), and then transported to the laboratory for measurement of cobalamin concentration, all in the same run. Percentage decrease in cobalamin concentration from baseline was analyzed by means of linear mixed modeling. RESULTS No differences in cobalamin values were identified between cats and dogs; therefore, data for both species were analyzed together. Median baseline serum cobalamin concentration was 424 ng/L (range, 178 to 1,880 ng/L). Values for serum samples stored with daylight exposure at room temperature were significantly lower over time than were values for refrigerated samples. Although values for refrigerated samples did not decrease significantly from baseline values over time, values for the other storage condition did; however, the mean percentage decrease for serum samples stored at room temperature was small (0.14%/h; 95% confidence interval, 0.07% to 0.21%/h). CONCLUSIONS AND CLINICAL RELEVANCE Overall, serum cobalamin concentration appeared stable for 5 days when feline and canine serum samples were refrigerated at 6°C. The effect of light and room temperature on serum cobalamin concentration, although significant, was quite small for samples stored with these exposures for the same 5-day period.
目的 评估储存条件和时间对犬猫血清样本中钴胺素浓度的影响。 设计 实验。 样本 来自9只客户拥有的猫和9只客户拥有的犬的血清样本。 步骤 从新鲜采集的血液样本中获取的血清被分成每只动物11份等分样本。一份等分样本（基线样本）常规用避光管运至实验室进行钴胺素测定；其余每份等分样本分别在冰箱（6°C；n = 5）或室温（20°C）下暴露于日光下（5份）保存24、48、72、96或120小时。随后将等分样本用铝箔包裹，冷冻（-20°C），然后全部在同一批次中运至实验室测定钴胺素浓度。通过线性混合模型分析钴胺素浓度相对于基线的下降百分比。 结果 未发现猫和犬之间钴胺素值存在差异；因此，对两个物种的数据进行了合并分析。血清钴胺素基线浓度中位数为424 ng/L（范围为178至1880 ng/L）。室温下暴露于日光保存的血清样本的值随时间显著低于冷藏样本的值。尽管冷藏样本的值随时间未从基线值显著下降，但其他储存条件下的样本值下降了；然而，室温下保存的血清样本平均下降百分比很小（0.14%/小时；95%置信区间为0.07%至0.21%/小时）。 结论及临床意义 总体而言，当猫和犬的血清样本在6°C冷藏时，血清钴胺素浓度在5天内似乎保持稳定。对于在相同5天期间内暴露于这些条件下保存的样本，光照和室温对血清钴胺素浓度有影响，尽管显著，但相当小。
