DNA/RNA damage assays

DNA is arguably one of the most biologically significant targets of cellular stress. DNA may be damaged by a variety of endogenous and exogenous sources, and the damage may take various forms:

• Oxidative DNA damage refers to the oxidation of specific bases
• Hydrolytic DNA damage involves the deamination or total removal of individual bases
• DNA strand breaks involve a cut in one or both strands; double-strand breaks are especially dangerous and can be mutagenic
• Pyrimidine dimers are formed most often from ultraviolet radiation
• Polycyclic aromatic hydrocarbons are often formed from exposure to chemical carcinogens

Universal DNA Damage: Comet Assay

The Comet Assay is a well-published method to detect various types of DNA damage in intact cells by electrophoresis. Damaged DNA is easily distinguished from healthy DNA by light microscopy; the damaged DNA moves farther when current is applied, creating a “comet” shape (see below).

Oxidative DNA Damage: 8-OHdG

8-hydroxydeoxyguanosine (8-OHdG) is the most common marker for oxidative DNA damage and can be measured in virtually any species. It is formed and enhanced most often by chemical carcinogens.

The OxiSelect™ Oxidative DNA Damage ELISA provides a highly sensitive method for measuring 8OHdG formation. Detect as little as 100 pg/mL in DNA isolated from urine, serum, cells and tissues.

Oxidative RNA Damage: 8-OHG

Like its DNA counterpart 8-OHdG above, 8-OHG (8-hydroxyguanosine) is the most common marker for oxidative RNA damage.

The OxiSelect™ Oxidative RNA Damage ELISA has a detection limit of 300 pg/mL and is suitable for use with cells, tissues, serum, urine or cerebrospinal fluid.

Hydrolytic DNA Damage: AP Sites

Loss of DNA bases can be particularly mutagenic, and if left unrepaired these AP (apurinic /apyrimidinic) sites can inhibit transcription. The OxiSelect™ DNA Damage Quantitation Kit (AP sites) provides a highly sensitive method for quantitation of AP sites. Quantify as few as 4-40 AP sites per 105 bp of DNA in tissue or cell lysates.

DNA Double-Strand Breaks

Double-strand breaks (DSB) in DNA are among the most dangerous types of DNA damage. One of the first responses to DSBs in mammalian cells is the phosphorylation of the Ser139 residue of a histone variant, H2AX, which occurs within seconds at the site of the damage. This phosphorylation causes chromatin condensation and appears to play an important role in recruitment of repair factors.

The OxiSelect™ DNA Double-Strand Break Staining Kit detects DSBs in cultured cells.

UV-Induced Damage:  Pyrimidine Dimers

Absorption of ultraviolet radiation can damage DNA by the formation of pyrimidine dimers. The two main forms of pyrimine dimers are cyclobutane pyrimidine dimers (CPD) and pyrimidine (6-4) pyrimidone photoproducts (6-4PP).

• ELISA kits to measure CPD or 6-4PP in DNA samples isolated from cells or tissues
• Cell-Based ELISA kits for use on intact cells
• Immunostaining kits for visualization by fluorescence microscopy

BPDE DNA Adduct Assay

Benzo(a)pyrene diol epoxide (BPDE) is a mutagen that may create adducts with DNA as well as proteins. It is a derived from benzo(a)pyrene which is polycyclic aromatic hydrocarbon (PAH), a family of chemical carcinogens commonly found in environmental pollution.

For more information about all protein oxidation & nitration assays to accurately measure oxidative and nitrative protein damage, Lipid peroxidation assays to quantify stable by-products of lipid peroxidation, reactive oxygen species (ROS) assays to measure ROS with high sensitivity in intact cells, cell lystaes or blood samples and all antioxidant assays for quantifying antioxidant capacity or specific antioxidant enzymes, please contact our technical support.