Reactive oxygen and nitrogen species (RONs) affect normal physiological processes and pathological conditions. In spite of the development of analytical and technological advancements in the detection and determination of RONs, there is a growing demand to achieve more rapid and accurate detection and determination of RONs and also of redox stress. In order to satisfy such a demand, we chose to prepare this current volume which comprises 27 chapters contributed by world-renowned experts on the state– the-art analytical and technological aspects of the detection and determination of RONs, and oxidative, nitrative, nitrosative, and redox stresses in biological systems, in vitro and in vivo. There is a need to establish biomarkers for the oxidative stress-induced genetic d- age in cellular and animal models. This need is addressed herein by offering protocols for (1) the generation of stable oxidative stress-resistant phenotypes of Chinese hamsters ?broblasts, (2) in vivo detection and measurement of free radicals and oxygen, (3) in vivo determination of tissue and DNA damage as a result of radical exposure, and (4) in vivo and in vitro monitoring of footprints of free-radical and antioxidant reactions. In the s- tions dedicated to the analysis of antioxidants and their metabolites, we describe methods for the analysis of phenolic acids and ?avonoids, eugenol antioxidants, and the recycling of ascorbic and lipoic acids. We also report on cellular reductive capacity, determination of glutathione, mitochondrial transmembrane potential, and cytotoxicity in cardiomyocytes under RONs stresses.