The Question

This Sunscreen Made Of DNA Gets Stronger The Longer It's In The Sun

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The sun is your best friend — until it's your worst enemy. Sit out on the beach too long, and you won't just get a sunburn. You'll literally burn up the DNA in your skin. When that happens, you leave yourself open to premature aging, liver spots, and worst of all, cancer. But if you take a pile of DNA, make it into a ultra-thin film, and wrap yourself in it like it's cellophane, you might be using the most advanced sun-care solution in the world.

DNA film structure. Scanning electron micrographs of (a,b) a 0.0031 mg/mm2 surface density DNA film exposed only to ambient UV light, (c,d) a 0.0031 mg/mm2 DNA film irradiated with a dosage of 320 J/cm2 UVA light (365 nm), and (e,f) a 0.0031 mg/mm2 DNA film irradiated with a dosage of 320 J/cm2 UVB light (302 nm). Scale bars in the left and right columns of images respectively denote 2 μm and 400 nm.

As Easy As D-N-A

So this all sounds a little out there, but according to tests carried out by biomedical engineering professor Guy German, a film made of crystalline DNA isn't just great at absorbing UV rays, it only gets better over time. In other words, the more light that this film is exposed to, the more light it is capable of protecting you from. The film is optically transparent, meaning visible light passes through to let us see through it, but it won't let UV radiation outside of the visible spectrum through. It's also been found to be hygroscopic, meaning that it helps skin absorb and hold water better. That's right: it's a moisturizer too.

While all signs are pointing to this crystallized DNA film as the sunscreen of the future, Professor German has even bigger plans for it as a protective bandage. By keeping wounds hydrated and protecting them from the elements, it could be instrumental to faster healing rates in extreme environments. It would still be transparent, too, so you wouldn't have to peel off your DNA "Band-Aid" to find out how your cut is healing. The result? Potentially, a go-anywhere salve so you won't have to call up mom to kiss your boo-boos better over satellite phone.

Tanning Without Protection

Maybe forging a shield from the very building blocks of life seems like overkill against a little bit of sunshine. That's because you don't know how bad a little sunshine could be. Suntans are just the body's way of throwing up a bulwark against the radiation, since the increased melanin in the skin reflects some of the sunlight back. But not all of it.

When the body's ability to create more melanin breaks down (and it doesn't take long for that to happen to the pale-skinned among us), that's when the trouble starts. And traditional sunscreen might not be enough to stop it. One study from 2006 found that if the sunscreen isn't applied properly, the long-term effects of the sun can be just as bad or worse as if it wasn't worn at all. The lesson is to make sure you are using enough sunscreen (you'll want full coverage), that you are reapplying it often enough (about once every two hours), and that you have the patience to wait for the impenetrable force field we'll someday use.

Which sunscreen should you choose?

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