Objectives: Oxidation–reduction potential (ORP) measurement can demonstrate the extent of oxidative stress in patients with severe illness and/or injury. A novel ORP diagnostic platform using disposable sensors (RedoxSYS) has been validated by comparison to mass spectrometry, but the optimal methods of sample handling for best performance of the device have not been described.

Methods: We sought to optimize ORP measurement in human plasma under controlled conditions. We hypothesized that the anticoagulant, freeze–thawing, and storage duration would influence measured ORP levels.

Results: The platform was sensitive to exogenous oxidation with hydrogen peroxide and reduction with ascorbic acid. Plasma anticoagulated with heparin was more sensitive to differences in ORP than plasma prepared in citrate. ORP measurements decreased slightly after a freeze–thaw cycle, but once frozen, ORP was stable for up to one month.

Discussion: We confirm that ORP detects oxidative stress in plasma samples. Optimal measurement of plasma ORP requires blood collection in heparin anticoagulant tubes and immediate analysis without a freeze–thaw cycle.

目标：氧化还原电位（ORP）测量可以证明严重疾病和/或伤害患者的氧化应激程度。通过与质谱法进行比较，已验证了使用一次性传感器（RedoxSYS）的新型ORP诊断平台，但尚未描述用于使设备达到最佳性能的最佳样品处理方法。

方法：我们试图在受控条件下优化人血浆中的ORP测量。我们假设抗凝剂，冻融和储存时间会影响测得的ORP水平。

结果：该平台对过氧化氢的外源氧化和抗坏血酸的还原均敏感。肝素抗凝的血浆对ORP差异的敏感性比柠檬酸盐制得的血浆更为敏感。冻融循环后，ORP的测量值略有下降，但是一旦冻结，ORP可以稳定长达一个月。

讨论：我们确认ORP可检测血浆样品中的氧化应激。血浆ORP的最佳测量需要在肝素抗凝管中收集血液并立即进行分析，而无冻融循环。