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

Skin icons can tap into promise of smartwatch

You have heard it before: smartwatches are cool wearables but critics remind us of the fact that their small size makes many actions cumbersome and they question how many people will really have them on their ...

Samsung phones cleared for US government use

Samsung Electronics Co. said Tuesday some of its Galaxy mobile devices were approved by the National Security Agency for use with classified U.S. government networks and data, a boost to the company's efforts to expand in ...

Review: Apple Pay in action

If there ever comes a day I can ditch my wallet and use my phone to pay for everything, I'll look back to my first purchase through Apple Pay: a Big Mac and medium fries for $5.44. That wallet-free day won't ...

Samsung seeks boost from redesigned Note

The latest version of Samsung's popular big-screen Galaxy Note has gone on sale at a crucial time for the South Korean company as it suffers a rapid decline in profit from its global smartphone business.

Amazon, Simon & Schuster sign book retail deal

Amazon has reached a deal with American book publisher Simon & Schuster, the companies said, though the e-commerce giant remains at loggerheads with France's Hachette over e-book pricing.