This article talks about how researchers at Stanford University have developed a technique that can temporarily make parts of a living mouse transparent using a safe, common food dye called tartrazine. The dye works by altering how light travels through tissue reducing light scattering and allowing it to pass through and reflect from deeper structures like blood vessels and organs.

This effect is achieved by adjusting the tissue’s refractive properties using principles related to the Kramers-Kronig relations. As a result, researchers were able to observe internal biological processes, such as muscle movements in the digestive system, in real time without invasive procedures.

The transparency develops within minutes of applying the dye and is reversible once it is washed off or naturally cleared from the body. Scientists hope this technology could eventually improve medical imaging, assist in early disease detection, and make procedures like blood draws and laser treatments easier.