8-Hydroxydeoxyguanosine (8OHdG)

8-Hydroxydeoxyguanosine (8OHdG) is a modified base that occurs in DNA due to attack by hydroxyl radicals that are formed as byproducts and intermediates of aerobic metabolism and during oxidative stress. There is increasing evidence to support the involvement of free radical reactions in the damage of biomolecules that eventually lead to several diseases in humans, such as atherosclerosis, cerebral and heart ischemia-reperfusion injury, cancer, rheumatoid arthritis, inflammation, diabetes, aging, and neurodegenerative conditions, such as Alzheimer’s disease.

Image: Alzheimer's Disease brain showing immunohistochemical staining of oxidized RNA in neurons. Tissue sections were formalin-fixed, paraffin embedded and pretreated with 10 ug/ml proteinase K for 40 minutes at 37^OC followed by staining with a 1:200 dilution of 8-hydroxyguanosine antibody.

8OHdG has become increasing popular as a sensitive, stable and integral marker of oxidative damage in cellular DNA. Biomonitoring in humans has demonstrated that 8OHdG can be excreted in the urine, and that a significant increase is caused by exposure to tobacco smoke and ionizing radiation. Because 8OHdG is so well correlated with oxidative stress and damage to DNA, which leads to degenerative disease states, the development of an antibody that can be used to study DNA damage has numerous applications. In addition to the direct study of DNA damage within cells, this antibody has applications in the development of immunoassays that can monitor 8OHdG excretion in the urine and serve as a biomarker of oxidative stress.