Innovations. DNA detectives.

To understand the many potential causes and resulting consequences of DNA damage, scientists first need methods to detect it. Canadian scientists X. Chris Le and Michael Weinfeld, with help from U.S. molecular biologist Steven Leadon, developed a selective, sensitive technique for measuring DNA damage. The scientists combined a thymine glycol antibody with thymine glycol to selectively tag a specific type of DNA damage. They then added a second antibody with fluorescing properties, and used laser-induced fluorescence to identify the damaged portion of the tagged DNA. The fluorescence can be quantified, with higher levels of fluorescence indicating higher DNA damage. The technique was shown to find 1 damaged base in 1 billion normal bases. This level of sensitivity could allow the measurement of DNA damage resulting from clinical levels of radiation, and may allow scientists to establish a day-to-day baseline for DNA damage. From this baseline, it would be possible to ascertain the levels of damage that a cell can tolerate, as well as how much damaged it is capable of repairing on a daily basis.