MitoCheck^® Complex II/III Activity Assay Kit

Complex III (CoQ cytochrome c oxidoreductase) is an essential protein for mitochondrial oxidative phosphorylation. Complex III functions as both a gatekeeper for mitochondrial respiration and as a major source of reactive oxygen species III. It accepts electrons from complexes I and II in the form of QH₂, the reduced form of the electron carrier ubiquinone. Once bound to complex III, QH₂ undergoes a series of redox reactions, known as the Q-cycle. During the Q-cycle, electrons are passed from QH₂ onto cytochrome c via the Rieske iron-sulfur protein and cytochrome c₁ resulting in the translocation of 4H⁺ and the generation of 0₂^•-. Cayman's MitoCheck^® Complex II/III Activity Assay measures the reduction of excess cytochrome c (550 nm absorbance) as catalyzed by complex III. This assay is coupled to succinate co-enzyme Q oxidoreductase (complex II) for the generation of QH₂. Due to the dependence on complex II activity, a counter-screen for complex II activity (Item No. 700940) should be performed in order to truly measure complex III activity. For the use of this kit with other types of tissue mitochondria, please see Cayman's MitoCheck^® Mitochondrial (Tissue) Isolation Kit (Item No. 701010).

Needed but not supplied: Please download the kit booklet to verify if UltraPure Water (Milli-Q or equivalent) or any other components are needed for this assay.

WARNING This product is not for human or veterinary use.

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Lei, S., Sun, R.-z., Wang, D., et al. Increased hepatic fatty acids uptake and oxidation by LRPPRC-driven oxidative phosphorylation reduces blood lipid levels. Front. Physiol. 7, 270 (2016).