Johns Jennifer L, Moorhead Kaitlin A, Hu Jing, Moorhead Roberta C
Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States.
Department of Comparative Medicine, Stanford School of Medicine, Stanford, CA, United States.
Front Vet Sci. 2018 Feb 15;5:3. doi: 10.3389/fvets.2018.00003. eCollection 2018.
Clinical pathology testing of rodents is often challenging due to insufficient sample volume. One solution in clinical veterinary and exploratory research environments is dilution of samples prior to analysis. However, published information on the impact of preanalytical sample dilution on rodent biochemical data is incomplete. The objective of this study was to evaluate the effects of preanalytical sample dilution on biochemical analysis of mouse and rat serum samples utilizing the Siemens Dimension Xpand Plus. Rats were obtained from end of study research projects. Mice were obtained from sentinel testing programs. For both, whole blood was collected terminal cardiocentesis into empty tubes and serum was harvested. Biochemical parameters were measured on fresh and thawed frozen samples run straight and at dilution factors 2-10. Dilutions were performed manually, utilizing either ultrapure water or enzyme diluent per manufacturer recommendations. All diluted samples were generated directly from the undiluted sample. Preanalytical dilution caused clinically unacceptable bias in most analytes at dilution factors four and above. Dilution-induced bias in total calcium, creatinine, total bilirubin, and uric acid was considered unacceptable with any degree of dilution, based on the more conservative of two definitions of acceptability. Dilution often caused electrolyte values to fall below assay range precluding evaluation of bias. Dilution-induced bias occurred in most biochemical parameters to varying degrees and may render dilution unacceptable in the exploratory research and clinical veterinary environments. Additionally, differences between results obtained at different dilution factors may confound statistical comparisons in research settings. Comparison of data obtained at a single dilution factor is highly recommended.
由于样本量不足，啮齿动物的临床病理检测往往具有挑战性。在临床兽医和探索性研究环境中，一种解决方案是在分析前对样本进行稀释。然而，关于分析前样本稀释对啮齿动物生化数据影响的已发表信息并不完整。本研究的目的是利用西门子Dimension Xpand Plus评估分析前样本稀释对小鼠和大鼠血清样本生化分析的影响。大鼠来自研究项目结束时的研究。小鼠来自哨兵检测项目。对于两者，通过终末心脏穿刺将全血收集到空管中并收获血清。对新鲜和解冻的冷冻样本直接进行生化参数测量，并以2至10的稀释倍数进行测量。根据制造商的建议，使用超纯水或酶稀释剂手动进行稀释。所有稀释样本均直接从未稀释样本中生成。在稀释倍数为4及以上时，分析前稀释在大多数分析物中导致了临床上不可接受的偏差。根据两种可接受性定义中较为保守的一种，总钙、肌酐、总胆红素和尿酸的稀释诱导偏差在任何程度的稀释下都被认为是不可接受的。稀释常常导致电解质值低于检测范围，从而无法评估偏差。稀释诱导偏差在大多数生化参数中不同程度地出现，在探索性研究和临床兽医环境中可能使稀释不可接受。此外，在不同稀释倍数下获得的结果之间的差异可能会混淆研究环境中的统计比较。强烈建议比较在单一稀释倍数下获得的数据。
