Assays for Measuring and Quantifying DNA Damage

Exposure to ionizing radiation or agents that induce DNA double-stranded breaks (DSBs), which is one of the most damaging types of lesions in DNA, can result in damage to cells and/or tissues.  Thiscan lead to illness (i.e., Acute Radiation Syndrome, Cancer) or death.  Identifying the amount of exposure to a DNA DSB-causing agent can be useful in determining the need for further testing, avoidance or modification of certain medical procedures, and/or types of medical treatments.

Strand breaks can be identified and quantified in situ by detecting phosphorylated histone protein γ-H2AX (gamma-H2AX) foci formed at DSBs.  The National Cancer Institute’s Developmental Therapeutics Branch have developed an assay for simultaneously quantifying the amount of γ-H2AX and total H2AX.  The ratio of γ-H2AX/H2AX provides reliable data that is independent of cell number, cell viability, cell lysis efficiency, and laboratory operator variability.  The assay is both sensitive and specific, having a 100-fold quantitative range with sensitivity of 5 pM for γ-H2AX and 50 pM for H2AX.

Competitive Advantages:

• High sensitivity and specificity -100 fold quantitative range with sensitivity of 5 pM for γ-H2AX and 50 pM for H2AX
• Can be performed on different types of samples ranging from cells, blood, and tissues

Commercial Applications:

Assay for measuring the DNA damage caused by ionizing radiation such as X-rays, environmental agents such as UV light, mutagenic chemicals, and cigarette smoke, and chemotherapeutic agents such as bleomycin and topotecan.