PressSplit
White house mouse reflected on table (symbolic image). © blickwinkel/Imago
The examination represents a decisive breakthrough in detecting what is hidden under the skin without surgery.
Scientists have discovered a surprisingly simple way to look inside the body. They used a yellow food dye found in Doritos to create mice that are transparent. In a series of experiments that could have come from a science fiction movie, researchers at Stanford University massaged a solution containing tartrazine, the chemical found in the food dye known as “Yellow No. 5,” onto the stomachs, scalps and hind legs of mice.
About five minutes later, the mice’s opaque skin temporarily transformed into a living window that revealed branching blood vessels, muscle fibers and intestinal contractions, they report on Thursday (September 5). in the magazine Science.
Read The Washington Post free for four weeks
Your quality ticket of washingtonpost.com: Get exclusive research and 200+ stories four weeks free.
Dye makes mice temporarily transparent
These results may sound like magic, but they are based on the fundamentals of optics – and are an important step on the long road to see what is beneath the surface of the body without a scalpel“You can see through the mouse. I’ve been working in optics for 30 years and I found this result stunning,” said Adam Wax, a program officer specializing in biophotonics at the National Science Foundation, one of the funders of the research.
The technique could help scientists answer long-standing questions in biology – for example, it allows researchers to observe a mouse’s brain activity, including in the deepest parts of the brain. It could be used to diagnose deep-seated tumors without surgery, locate a vein for a blood draw or make cosmetic procedures such as tattoo removal more precise, said Guosong Hong, a materials scientist at Stanford and one of the study’s leaders.
A row of Doritos in a supermarket. © Depositphotos/Imago
“We don’t make a real invisibility cloak”
“It’s not like Harry Potter. … We’re not making a real Invisibility Cloak” said Christopher Rowlands, a biophotonics researcher at Imperial College London who was not involved in the study but plans to test the technique in his lab. While the feat may not match the most fantastic notions of invisibility, Rowlands called the new work “a big deal,” allowing researchers to see 10 times deeper into living tissue with a simple topical application of a common food dye. “If some of my colleagues aren’t excited, it’s because they haven’t understood the implications,” he said.
How does bright yellow food coloring make tissue transparent? To understand why this is the case, you first have to consider why things look opaque in the first place. The parts of our bodies – cell membranes, proteins, fluids – all cause light to bend or bend.
If light is refracted just once – think of a sunbeam hitting a pane of glass – the image it carries is still largely clear. But if the light is repeatedly refracted by fluids, proteins and other cellular mixtures, it is scattered in many directions. All this scattered light, says Rowlands, makes it difficult to see through – “like watching TV through a glass of milk.”
Altered light refraction makes mice transparent
In 1897, science fiction writer HG Wells published The Invisible Man, the story of a scientist who invented a serum that altered the way the body’s cells refract light, making him invisible. This is conceptually similar to what the Stanford researchers did.
By applying principles from textbook physics, the researchers were able to look for molecules that they predicted, when absorbed by the body, would alter the way light refracts in biological tissue. They came across tartrazine dissolved in water. But the proof was in the experiment. They soaked a piece of raw chicken in a tartrazine solution and found that as they increased the amount of tartrazine, the chicken became clear. When they applied this solution to the skin of mice, they saw the internal organs become visible. The tartrazine reduced refraction, light scattered less, and the tissue appeared clear.
Other exciting research areas
Researchers are testing ultrasound technology in the fight against drug addiction.
Scientists believe they have found a way to recycle clothing.
Munich researchers find important clues as to how life on Earth began.
After washing off the dye, the tissue returned to normal, and the scientists reported “minimal systemic toxicity” in the mice. Although tartrazine is used as a common food coloring, this technique has not yet been tested on humans, and it is not the kind of effect that occurs at the tiny concentrations that result when people get a little dust from flavored chips on their hands.
It is unclear when the technology can be tested on humans
Hong said his lab doesn’t work with human tissue or subjects, noting that human experiments require ethical approval, so it’s unclear when researchers might try this technique on people. Rowlands said he’s intrigued by the possibility of finding other dyes that have the same effect at lower doses.
Francesco Pavone, a physicist specializing in biophotonics at the University of Florence, said the study would spark a race to find applications. “The ultimate goal is human application, and so far we are not there,” Pavone said. “The biggest breakthrough I see here is that it could finally be accessible to humans.”
About the author
Carolyn Johnson is a science reporter. She previously covered health care and health care affordability for consumers.
We are currently testing machine translations. This article has been automatically translated from English into German.
This article was first published in English on September 5, 2024 at the “Washingtonpost.com“ was published – as part of a cooperation, it is now also available in translation to readers of the IPPEN.MEDIA portals.
