In an experiment designed to explore how it could be possible to see through opaque biological matter, scientists from Stanford theorized that certain dyes would absorb light from certain parts of the spectrum. So they created a solution using a large amount of yellow number 5 food dye—otherwise known as tartrazine, commonly used to color products such as Doritos—and applied it to portions of living mouse bodies. While the solution remained topically, the scientists were able to see the mice’s internal organs; their skin became opaque again once the solution was rubbed off, with no apparent toxic effects. The significance? Being able to look through humans’ skin could help doctors diagnose a range of medical conditions that exist within and just below the skin, without surgery, and could also help better guide procedures such as catheter insertion.
