A Sensitive and High Throughput Method for the Rapid Quantification of Radiation Induced DNA Damage

Interests: Imaging Agents

Published: September 3, 2019

Lead Inventor: Stephen Kron

Current high throughput assays to quantify radiation induced DNA damage are limited by low sensitivity and cannot reliably detect radiation induced damage lower than 10Gy (J/Kg), despite the fact that doses as low as 0.5Gy can confer elevated cancer risk. Improved assays are highly desirable to triage patients exposed to radiation, since increased cancer risk can be conferred even without the onset of symptoms.
DNA damage caused by radiation is mediated by reactive oxygen species (ROS) that oxidize DNA nitrogenous bases, resulting in base mispairings and ultimately oncogenic mutations. One such commonly occurring oxidized nitrogen base is 5-formyladine (5-FODU), which occurs when thiamine is oxidized. The investigators synthesized a pro-fluorescent hydrazine probe that can react with the aldehyde in 5-FODU, allowing this DNA damage byproduct to act as a proxy for quantifying the DNA damage itself.
The invention is a method for the quantification of DNA damage in which a pro-fluorescent hydrazide, also known as an aldehyde reactive probe (ARP), is incubated with cells and will react with 5-FODU in the cellular DNA to form a fluorescent complex. The cellular fluorescence can then be measured using flow cytometry and the results can be used to quantify the extant of DNA damage present in the sample.
The investigators validated the method and found it capable of detecting the presence of 5-FODU when it occurred as a result of exposure to radiation doses as low as 2Gy.