Flores Carlos Fernando Yauli, de Las Mercedes Hurtado Pineda Ángela, Bonilla Victoria Maritza Cevallos, Sáenz-Flor Klever
Clinical Laboratory, Hospital General Docente Ambato, Ambato, Ecuador.
Clinical Laboratory, Faculty of Health Sciences, Universidad Técnica de Ambato, Ambato, Ecuador.
EJIFCC. 2020 Mar 20;31(1):46-55. eCollection 2020 Mar.
The analytes stability on serum and plasma are critical for clinical laboratory, especially if there is a delay in their processing or if they need to be stored for future research. The objective of this research was to determine the stability of KEDTA-plasma and serum on different storage conditions.
A total of thirty healthy adults were studied. The serum/plasma samples were centrifuged at 2000g for 10 minutes. Immediately after centrifugation, the serum/plasma analytes were assayed in primary tubes using a Cobas c501 analyzer (T0); the residual serum/plasma was stored at either 2-8°C or -20°C for 15 (T15) and 30 days (T30).Mean concentrations changes in respect of initial concentrations (T0) and the reference change values were calculated. For assessing statistical difference between samples, the Wilcoxon ranked-pairs test was applied.
We evidenced instability for total bilirubin, uric acid, creatinine and glucose at T15 and T30 and stored at -20°C (p<0.05). However, potential clinical impact significance were observed only for total bilirrubin T30 at -20°C, and creatinine T30 at 2-8°C.
Our results had shown that storage samples at -20°C is a better way to preserve glucose, creatinine, and uric acid. Therefore, laboratories should freeze their samples as soon as possible to guarantee proper stability when there is need to repeat analysis, verify a result, or add a laboratory testing.
对于临床实验室而言，血清和血浆中分析物的稳定性至关重要，尤其是在样本处理出现延迟或需要储存以备未来研究之用时。本研究的目的是确定乙二胺四乙酸钾（KEDTA）抗凝血浆和血清在不同储存条件下的稳定性。
共研究了30名健康成年人。血清/血浆样本以2000g离心10分钟。离心后立即使用Cobas c501分析仪在原始试管中检测血清/血浆分析物（T0）；剩余的血清/血浆分别在2-8°C或-20°C下储存15天（T15）和30天（T30）。计算相对于初始浓度（T0）的平均浓度变化以及参考变化值。为评估样本之间的统计学差异，应用了Wilcoxon配对秩和检验。
我们发现，总胆红素、尿酸、肌酐和葡萄糖在-20°C储存的T15和T30时不稳定（p<0.05）。然而，仅在-20°C下储存30天的总胆红素以及在2-8°C下储存30天的肌酐观察到了潜在的临床影响意义。
我们的结果表明，在-20°C下储存样本是保存葡萄糖、肌酐和尿酸的更好方法。因此，当需要重复分析、验证结果或增加实验室检测时，实验室应尽快冷冻样本以确保适当的稳定性。
