New Discovery with Mice

Scientists at Stanford University Achieve Transparent Tissues in Live Mice
Scientists from Stanford University have conducted an experiment that seems straight out of a sci-fi movie, successfully making certain tissues in live mice transparent. If this breakthrough can be applied to humans, it could revolutionize blood sampling and disease diagnosis.
The method used in the study is based on preventing light scattering in regions with different refractive indices within tissues.
Normally, tissues and the surrounding fluids scatter light because they have different refractive indices, causing a loss of transparency. However, if the refractive indices are equalized, light can pass through deeper tissues, creating a much clearer image.
To achieve this effect, researchers used a food dye called tartrazine. Tartrazine absorbs light at specific wavelengths, altering the refractive index of surrounding fluids and significantly reducing light scattering. Ou explained, “This dye is biocompatible, meaning it’s safe for living organisms. It’s also very inexpensive and highly effective-we only need to use a tiny amount for it to work.”
When applied to the skin of live mice, the tartrazine dye made blood vessels, organs, and even muscle movements in the digestive system visible.
Within minutes of application, the skin became transparent, and after the procedure, it could be washed off to restore its original state. Any dye that penetrated deeper into the body was eventually excreted through urine.
Since human skin is about ten times thicker than mouse skin, it remains uncertain whether this technique will be effective in humans. However, researchers plan to investigate this further.