Oxidative stress is commonly defined as a condition under which the generation of reactive oxygen species (ROS) within a cellular system exceeds the buffering capacity of endogenous antioxidant defenses. This leads to oxidative damage to lipids, DNA and proteins, and has been linked to aging, cancer and other diseases. One of the most commonly used markers of oxidative stress is carbonylation of proteins.

The RayBiotech Protein Oxidation (Carbonyl Content) Assay Kit provides a simple and accurate method for quantifying protein carbonyl content in plasma, serum, cell lysates and other biological liquid samples. Carbonyl content is determined by the derivatization of protein carbonyl groups with 2,4-dinitrophenyl-hydrazine (DNPH), resulting in the formation of stable dinitrophenyl (DNP) hydrazone adducts. These adducts can be measured spectrophotometrically at 375 nm, and the absorbance is directly proportional to the carbonyl content present in the sample.