Let’s be completely transparent about what this new breakthrough means. Researchers from Stanford University managed to make the skin of mice see-through after rubbing a solution on mice’s heads, abdomens and hind legs. This allowed the researchers to really get under the mice’s skin, so to speak, and see their underlying blood vessels, muscles and organs live in real-time as described by a recent publication in the journal Science.
And guess what, the solution wasn’t some kind of Infinity Stone-like magic or secret military-esque stuff used in the 2000 sci-fi movie Hollow Man. Nope, the main ingredient is something commonly found on Doritos. Yes, those kinds of Doritos. It’s the yellow no. 5 food dye otherwise known as tartrazine.
Now, before you start staring suspiciously at your yellow or orange hand after you’ve been grabbing fistfuls of Doritos, keep in mind that the research team led by Guosong Hong, PhD, an sssistant professor of materials science and engineering at Stanford, used a much higher concentration of tartrazine than normally found on chips. So, you shouldn’t normally be able to see the insides your hand while snacking on chips. That’s not unless something else terrible has happened.
This more concentrated tartrazine solution did work fairly quickly on the mice in the study. Just about five minutes after the researchers had rubbed their mice, presto, voilà, they could see the inner workings of the mice’s bodies. This transparency wasn’t permanent, though. Once the researchers washed the dye off the bodies of the mice, the furry, whiskered creatures returned to their old opaque selves. The study didn’t find any significant toxic effects for the mice either.
While this method may seem very mice right now, imagine what a medical game-changer it could be if it can eventually be applied to humans. Being able to look through the skin of humans could help doctors more readily diagnose different conditions without the use of surgery. This could encompass a range of different medical conditions that exist within and just below the skin. Such transparency could also help better guide medical procedures such as threading catheters into different blood vessels or removing things in and below the skin.
So, you may be “dying” to know how tartrazine can make skin so see-through. Well, it’s all about the optics. Transparent things such as glass are see-through because light can pass right through them without being bent. Putting substances like frosting on glass can make the glass less transparent because such substances begin bending or refracting the light in different ways. The more light gets refracted, the less transparent it becomes.
Just think of all the different cells, membranes and other stuff that’s in skin. And you’ll realize how much bending and refracting as a result can happen to light that tries to pass through the skin. This leaves skin typically quite opaque.
In order to turn skin more peekaboo, the researchers then looked for a substance that could reduce how much biological tissues refract light. The search revealed tartrazine as a potential candidate. And when they soaked a slice of raw chicken in tartrazine dissolved in water, the chicken turned clear. This made it clear this substance could decrease how much light refraction and scattering was occurring through tissue. Trying it on mice came next.
In theory such a mechanism could hold with human skin as well. But unless you are furry and have whiskers, you can’t be sure that what happens in mice will necessarily happen to you. And you won’t be able to figure this out by simply rubbing Doritos all over your body. Therefore, you’ll have to wait until studies with tartrazine can be conducted on humans and see what they show.