Hawkins Clare L, Davies Michael J
The Heart Research Institute, 7 Eliza Street, Newtown, Sydney, NSW 2042, Australia; Faculty of Medicine, Sydney Medical School, Sydney, NSW 2006, Australia.
Biochim Biophys Acta. 2014 Feb;1840(2):708-21. doi: 10.1016/j.bbagen.2013.03.034. Epub 2013 Apr 6.
Electron paramagnetic resonance (EPR) spectroscopy (also known as electron spin resonance, ESR, spectroscopy) is widely considered to be the "gold standard" for the detection and characterisation of radicals in biological systems.
The article reviews the major positive and negative aspects of EPR spectroscopy and discusses how this technique and associated methodologies can be used to maximise useful information, and minimise artefacts, when used in biological studies. Consideration is given to the direct detection of radicals (at both ambient and low temperature), the use of spin trapping and spin scavenging (e.g. reaction with hydroxylamines), the detection of nitric oxide and the detection and quantification of some transition metal ions (particularly iron and copper) and their environment.
When used with care this technique can provide a wealth of valuable information on the presence of radicals and some transition metal ions in biological systems. It can provide definitive information on the identity of the species present and also information on their concentration, structure, mobility and interactions. It is however a technique that has major limitations and the user needs to understand the various pitfalls and shortcoming of the method to avoid making errors.
EPR remains the most definitive method of identifying radicals in complex systems and is also a valuable method of examining radical kinetics, concentrations and structure. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn.
电子顺磁共振（EPR）光谱法（也称为电子自旋共振，ESR，光谱法）被广泛认为是检测和表征生物系统中自由基的“金标准”。
本文回顾了EPR光谱法的主要优缺点，并讨论了在生物学研究中如何使用该技术及相关方法来最大化有用信息并最小化假象。文中考虑了自由基的直接检测（在常温及低温下）、自旋捕获和自旋清除的应用（如与羟胺的反应）、一氧化氮的检测以及一些过渡金属离子（特别是铁和铜）及其环境的检测和定量。
谨慎使用该技术时，它可以提供有关生物系统中自由基和一些过渡金属离子存在的大量有价值信息。它可以提供有关存在的物种身份的明确信息，以及有关其浓度、结构、流动性和相互作用的信息。然而，这是一种有主要局限性的技术，用户需要了解该方法的各种陷阱和缺点以避免出错。
EPR仍然是识别复杂系统中自由基的最明确方法，也是研究自由基动力学、浓度和结构的有价值方法。本文是名为“研究活性氧的当前方法——利弊及膜蛋白生物物理学”特刊的一部分。客座编辑：克里斯汀·温特伯恩。
