DNA can be damaged by very low-energy radiation: How safe are 'eye-safe' lasers?

March 14th, 2014
That energetic particles damage DNA is not surprising. It is now appears that very low-energy OH radicals also damage DNA, with a propensity that depends on how vigorously OH rotates: rotationally 'hot' OH induce irreparable double breaks. These findings utilize OH formed in plasma created when intense IR femtosecond laser pulses propagate in water containing DNA. Industry characterizes as 'eye-safe' IR lasers. With such wavelengths being proficient at inducing DNA damage, how safe is 'eye-safe'?

Damage to DNA by high energy radiation constitutes the most lethal damage occurring at the cellular level. Surprisingly, very low-energy interactions - with OH radicals, for instance - can also induce DNA damage, including double strand breaks. It is known that single strand breaks in the DNA backbone are amenable to repair but most double strand breaks are irreparable. The propensity with which slow OH radicals damage DNA depends on their rotational energy: rotationally "hot" OH is more proficient in causing double breaks. These novel findings are from experiments conducted on DNA in a physiological environment. Intense femtosecond laser pulses are propagated through water (in which DNA plasmids are suspended), creating plasma channels within water, resulting in generation, in situ, of electrons and OH radicals. It is shown that use of long laser wavelength light (1350 nm and 2200 nm) ensures only OH-induced damage to DNA is accessed. It is noteworthy that industry presently characterizes as "eye-safe" lasers that emit at wavelengths longer than 1300 nm.

But it is such wavelengths that are proficient at inducing damage to DNA: how safe is "eye-safe" when DNA in the eye can be readily damaged?

Provided by Tata Institute of Fundamental Research

This Phys.org Science News Wire page contains a press release issued by an organization mentioned above and is provided to you “as is” with little or no review from Phys.Org staff.

More news stories

Netherlands bank customers can get vocal on payments

Are some people fed up with remembering and using passwords and PINs to make it though the day? Those who have had enough would prefer to do without them. For mobile tasks that involve banking, though, it is obvious that ...

How bees naturally vaccinate their babies

When it comes to vaccinating their babies, bees don't have a choice—they naturally immunize their offspring against specific diseases found in their environments. And now for the first time, scientists have discovered how ...

Binary star system precisely timed with pulsar's gamma-rays

Pulsars are rapidly rotating compact remnants born in the explosions of massive stars. They can be observed through their lighthouse-like beams of radio waves and gamma-rays. Scientists at the Max Planck Institute for Gravitational ...

Image: Hubble sees a dying star's final moments

A dying star's final moments are captured in this image from the NASA/ESA Hubble Space Telescope. The death throes of this star may only last mere moments on a cosmological timescale, but this star's demise is still quite ...

Earth flyby of 'space peanut' captured in new video

NASA scientists have used two giant, Earth-based radio telescopes to bounce radar signals off a passing asteroid and produce images of the peanut-shaped body as it approached close to Earth this past weekend.

Exoplanets 20/20: Looking back to the future

Geoff Marcy remembers the hair standing up on the back of his neck. Paul Butler remembers being dead tired. The two men had just made history: the first confirmation of a planet orbiting another star.