How scientists made mice transparent with food coloring from Doritos

Let’s be completely transparent about what this new breakthrough means. Researchers at Stanford University have managed to make the skin of mice translucent after rubbing a solution on the heads, abdomen and hind legs of mice. This allowed the researchers to actually crawl under the skin of the mice and see their underlying blood vessels, muscles and organs live in real time. as described in a recent publication in the journal Science.

And guess what, the solution wasn’t some Infinity Stone-like magic or secret military-like stuff used in the 2000 sci-fi movie. Hollow man. No, the main ingredient is something commonly found on Doritos. Yes, those kind of Doritos. It is the yellow No. 5 food coloring, also known as tartrazine.

Before you start staring suspiciously at your yellow or orange hand after grabbing handfuls of Doritos, keep in mind that the research team led by Guosong Hong, PhD, an assistant professor of materials science and engineering at Stanford, found a much higher concentration tartrazine than normally found on potato chips. So normally you shouldn’t be able to see the inside of your hand while eating chips. Unless something else terrible has happened.

This more concentrated tartrazine solution worked quite quickly on the mice in the study. Only about five minutes after the researchers rubbed their mice, they were able to see the inner workings of the mice’s bodies. However, this transparency was not permanent. After the researchers washed the dye from the mice’s bodies, the hairy, whiskered creatures returned to their old, opaque selves. The research also showed no significant toxic effects on the mice.

While this method may seem very silent at the moment, imagine what a medical game-changer it could be if it can eventually be applied to humans. By being able to see through people’s skin, doctors could more easily diagnose various conditions without having to resort to surgery. This can include a range of different medical conditions that occur within and just under the skin. Such transparency could also help better guide medical procedures, such as inserting catheters into different blood vessels or removing things in and under the skin.

So you may be “craving” to know how tartrazine can make skin so translucent. It’s all about the optics. Transparent things like glass are transparent because light can pass straight through them without being bent. Applying substances such as glaze to glass can make the glass less transparent, because such substances bend or refract light in different ways. The more light is refracted, the less transparent it becomes.

Just think of all the different cells, membranes and other things that make up the skin. And you will realize how much bending and refraction can occur as a result of light trying to penetrate the skin. This usually makes the skin quite opaque.

To make the skin more peek-a-boo, the researchers then looked for a substance that could reduce how much biological tissues refract light. The search revealed that tartrazine was a potential candidate. And when they soaked a slice of raw chicken in tartrazine dissolved in water, the chicken became clear. This made it clear that this substance could reduce the amount of light refraction and scattering through tissue. Then it was tried on mice.

In theory, such a mechanism could also apply to human skin. But unless you’re hairy and have whiskers, you can’t be sure that what happens to mice will necessarily happen to you. And you won’t find out by simply rubbing Doritos all over your body. Therefore, you will have to wait until studies with tartrazine can be conducted on humans and see what they show.