Sterilization is hands down one of the most important technologies ever developed by mankind, but though we’ve known how to do battle with bacterial pathogens in places like the operating room for decades, superbugs like MRSA and Clostridium difficile persist in hospital environments, often causing serious medical complications. But now, researchers at the University of Strathclyde in Glasgow have devised a novel means to drive dangerous pathogens to cell suicide by simply bathing them in a pleasant violet light.
Light-based sterilization is nothing new – ultraviolet light can do a number on pathogens, though it also does damage to humans – but the new method uses a narrow spectrum of visible, harmless light wavelengths known as HINS (High Intensity, Narrow Spectrum) light to do the trick. HINS light excites molecules within bacteria such that they produce a chemically lethal response, in essence pushing bacteria to kill themselves. But while it drives bacteria to cell suicide, it’s harmless to humans and therefore can be incorporated into existing lighting systems in clinical environments to provide continuous sterilization of surfaces and air.
Continuous sterilization, of course, keeps infectious bacterial pathogens from spreading around places like hospital wards, where immune systems are low and the chances of infection are high.And what of the violet hue? Some might find it a nice ambient addition to the usual bright-white aura of the average operating theater. But for the sake of consistency the team has also figured out how to integrate the HINS light with a combination of LED technologies to produce a warm white light that can be used alongside the usual hospital lighting scheme.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.


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why doesn't it harm humans?
My guess, it doesn't penetrate beyond the sheath of dead human skin cells?
Does it have that same effect on helpful bacteria? Have they tested it on superbugs specificly. What about long term exposure or exposure to internal organs?
Sounds interesting , how can we be sure evolution wont find a way ? I wonder how many generations it will take for bacteria to evolve resistance to this High Intensity Narrow Spectrum light ?
My understanding of the harm caused by the UV lights currently used for sterilization is that exposure to such light can potentially lead to damage to the eyes, even causing blindness. I have not heard of any other health problems from UV, but if anyone knows better, please post.
This is brilliant. @ geebob, that is probably it. It would take a while but evolution could overcome this. Possibly a very long while. Using a combination strategy would be even better. Find several such frequencies, more the better, then always use two or three of them together. Evolution will be late.
I've heard that the early antibiotics were so poorly filtered they actually contained the DNA coding for the antibiotics as well as for their defense. These were soon replaced by higher quality versions for *people* but the originals were still given to livestock for years after as growth promoters. And over-used at several times the rate as human overuse too.
These super bugs might have taken hundreds of years to arise if we hadn't dumped that DNA into the collective bloodstream of all our herds. Then without growth promotion it might have been a thousand years. Without rampant human overuse it may have taken longer than the current age of our species...just stupid.
But at least this should work for a heck of a long time. If only it could be used internally...
woah, woah, woah sterilization requires the death of all organisms, as in it would kill human cells too. It's not sterilization; it's disinfection. There's a pretty big difference there.
Seems the actual wavelength is not mentioned so I will add it here: The light's wavelength is 405nm.
If you keep it in the O.R. and in a special room where people who already have a harmful bacterial infection can go to be treated, then it should last a long time before nature figures out how to over come it. The cleaning people can also use it to clean the walls and floors of hospitals without the chance of exposing it to everyone in the hospital. It is well understood that be need certain bacteria and viruses in our body to live, so you don't want to kill them all without a means to restore the good bacteria and viruses.
my guess on why it doesnt harm humans while kill bacteria is because bacteria is completely different than human skin cells. i dont think bacteria has a cell wall like skin. and just a lot fo other differances in the build of the bacteria itself. people are huge and bacteria are small. easier to get rid of a full organism if you can affect its whole body relative to a few cells.
Kudos to the Scots! Sir Alexander would be beaming- like their brilliant light. Not only does it blast the little creepy critters- it's safe for humans ...AND ..doesn't poison the environment! I smell the Nobel prize! Well done!
I have to echo a question by an earlier poster caradoc. Our skin holds myriad number of bacterial organisms, some good, some not so much. But, on a healthy adult the percentage of good organisms vastly outweigh the bad. In effect the good keep the bad "in check." So what happens when you use this indiscriminate killer of those skin organisms? In effect use a WMD (Weapon of Mass Destruction) on them? Are you paving the way for more problems than you know?
So you know...this is also my basic argument against the wholesale use of antibiotics and such....we need to learn to properly live within the web of Life (that supports us) without conducting ourselves in such a fashion that rips it apart.
Just some thoughts...
@ JAYMCD84. Humans do not have cell wall for their skin cells, they have cell membranes which bacteria also have. You're thinking of cell wall for plants.
@ wpmcg I totally agree with you. We need to test how this affects our eyes, especially newborns before we put this in hospitals.
As for good bacteria inside us, I'm sure they'd be okay since that light can't penetrate pass our epidermis. (I hope)
It seems that if this was used in the OR and for cleaning like JamesDavis said, then nothing to crazy would happen. I always say "Just because you can do it doesn't mean you should." This technology seems like it could improve conditions in maybe tropical surgery areas, but I don't think it should become some mainstream thing in everybody's houses.
"can be incorporated into existing lighting systems in clinical environments to provide continuous sterilization of surfaces and air"
Dumbest thing I've read in a while. Can anybody tell me how superbugs evolved in to being?
This would make a fast way to periodically perform an extra sanitation, but continuous?!?
Good news! We've discovered a new way to kill most bacteria. Bad news! In our rush to monetize we've created a new epidemic of light resistant superbugs.
WHOA, WHOA, whoa, hey so the gross little germs will adventulally become even more super. Like superman bugs and they wont be harmed by light that is so powerful that it acually can kill people on the spot.So why do we still try. I'm sooooo lost how about yall?
Medical? What about food technology? Food processing plants, egg processors, restaurants, all would benefit from this technology.