Pawlik-Sobecka Lilla, Sołkiewicz Katarzyna, Kokot Izabela, Kiraga Aleksandra, Płaczkowska Sylwia, Schlichtinger Agnieszka Matylda, Kratz Ewa Maria
Department of Nervous System Diseases, Faculty of Health Sciences, Wroclaw Medical University, 51-618 Wroclaw, Poland.
Department of Laboratory Diagnostics, Faculty of Pharmacy, Wroclaw Medical University, Borowska Street 211a, 50-556 Wroclaw, Poland.
Diagnostics (Basel). 2020 Jan 19;10(1):51. doi: 10.3390/diagnostics10010051.
The present work aims at accessing the stability of biological material stored for diagnostic and scientific purposes. The influence of the temperature, storage time, and cyclic thawing on concentration stability of selected oxidative stress parameters in human serum was investigated. The study group consisted of 20 serum samples collected from healthy volunteers aged 18-52. The parameters whose reference ranges were not determined and to which validated determination methods did not correspond were examined by manual methods (FRAP and AOPP). Automatic methods were used to determine routine laboratory tests (albumin, total protein, bilirubin, uric acid) using the Konelab 20i analyzer. The samples were stored at various temperatures (room temperature, 4 °C, -20 °C, -80 °C) for max 6 months and were subjected to cyclic thawing at 1 month intervals. In order to check whether any differences between the concentrations of the studied parameters existed when the samples were stored in various conditions, the paired Student t-test or Wilcoxon test and comparison to desirable bias were applied. Based on the obtained results, it was found that the temperature and time of serum sample storage significantly affected the stability of the analyzed parameters and determined different shelf lives of serum samples for oxidative stress examination. Therefore, continuing the investigation concerning the impact of storage conditions on various serum parameters seems justified due to the discrepancy between the individual results obtained by different researchers and the inconsistencies between the results of scientific research and the applicable recommendations.
本研究旨在评估用于诊断和科学目的的生物材料的稳定性。研究了温度、储存时间和循环解冻对人血清中选定氧化应激参数浓度稳定性的影响。研究组由20份从18 - 52岁健康志愿者采集的血清样本组成。对于参考范围未确定且无相应有效测定方法的参数，采用手工方法（FRAP和AOPP）进行检测。使用Konelab 20i分析仪通过自动方法测定常规实验室检测项目（白蛋白、总蛋白、胆红素、尿酸）。样本在不同温度（室温、4℃、-20℃、-80℃）下储存最长6个月，并每隔1个月进行一次循环解冻。为了检查样本在不同条件下储存时所研究参数的浓度是否存在差异，应用了配对学生t检验或威尔科克森检验以及与理想偏差的比较。根据所得结果发现，血清样本的储存温度和时间显著影响分析参数的稳定性，并确定了用于氧化应激检测的血清样本的不同保质期。因此，由于不同研究人员获得的个体结果之间存在差异以及科研结果与适用建议之间存在不一致，继续研究储存条件对各种血清参数的影响似乎是合理的。
