Turning skin invisible

By Casey Frye, CCNN Writer

For years, scientists have been working on techniques to make different parts of the body clear like plastic, so they can sneak a peek inside. While there are already ways to do this, current techniques can be expensive and not even allow visibility all the way inside! However, thanks to research from the RIKEN Center for Developmental Biology, there is now a simple, cheap way to do this with a special syrup.

The first ingredient is as basic as basic gets. I’ll give you a hint: It’s clear, liquid, and can be slippery when on a smooth floor. If you guessed water, you’re correct!

The second ingredient they used was fructose. This sounds like something toxic doesn’t it? Actually it’s just a type of sugar, found in things like apples, pears, and honey. Why would they use sugar? Part of the reason is because this sugar has the same refractive index – a fancy way of saying how light travels through something – as cells in the brain. When things with the same refractive index are mixed together, much more light is able to pass through, and it becomes more transparent.

However, when the scientists combined fructose and water, a Maillard reaction occurred. A what?! A Mallard duck? No, no, a Maillard reaction. This is the reaction that occurs when sugar is combined with proteins and heat, resulting in a brown-colored substance. A good example is when you cook steak, the heat of the fire combines with the sugars and proteins in the meat to change its color from reddish to brown! For example, if you cook duck meat…

Back on track! When scientists mixed brain cells with  fructose, they turned brown, which is why the scientists decided to add one more ingredient. The final ingredient in the syrup? Alpha-thioglycerol  (honestly, where do they come up with these names?!). This tricky sounding chemical was used to stop the brain from browning in the Maillard reaction.


After three days of swimming inside this special syrup, the brain turned basically see-through! Scientists call this trick See Deep Brain, or SeeDB for short.

This technique is safe, simple, and cheap. It also allows researchers to see more inside the brain than ever before, and understand how it works. Now, don’t go mixing syrup and water in the kitchen, hoping to turn invisible by drinking it all. The formula is not as simple as that!

Images courtesy of RIKEN.