ROS logo







Vascular Medicine Institute

University of Pittsburgh

Free Radicals and Reactive Oxygen Species (ROS)

Free radicals are molecules possessing unpaired electrons and thus are reactive and short-lived in a biological setting. Dependent upon the site of and rate of production (concentration), free radicals can mediate both detrimental modifications to biomolecules and/or participate in beneficial cellular signal transduction. Reactive oxygen species (ROS) comprise both free radical and non-free radical oxygen intermediates such as hydrogen peroxide (H2O2), superoxide (O2•-), singlet oxygen (1O2), and the hydroxyl radical (OH). These species are formed by the metabolism of oxygen in mitochondria, ionizing radiation, UV radiation, xenobiotic catabolism and a variety of cellular enzymes including Xanthine Oxidoreductase (XOR), NADPH oxidases (Nox), Aldehyde Oxidase (AO), mitochondrial electron transport proteins and dysfunctional (uncoupled) Nitric Oxide Synthases (NOS).  Once thought to play an exclusively negative role by inducing cellular/tissue damage, degrading bioactive nitric oxide (NO) and enhancing phagocytic antimicrobial action, ROS have recently been identified as critical mediators of cell signaling. For example, ROS participate in the signaling events controlling cell proliferation, hypertrophy, migration, wound healing, angiogenesis, neuronal signaling, vasomotor tone, and thyroid hormone metabolism. Therefore, there is broad interest in reliable and sensitive methods to detect and quantify these reactive species.

The Free Radical and ROS Facility is designed to aid investigators in the detection, quantification and imaging of reactive species in multiple model systems, as such we offer assistance with experimental design and execution of the following assays: