Scientists use common yellow food dye tartrazine to make skin transparent, see internal organs inside body
tartrazine, a common food dye, can make the skin of living mice temporarily transparent. This innovative technique allows scientists to observe internal organs without invasive procedures. The research, detailed in the journal Science, marks a significant advancement in biomedical imaging. This discovery, reminiscent of HG Wells' "The Invisible Man," provides a new method to visualize internal structures effectively.
How It Works
The transparency is achieved by altering the refractive indices of the tissues. Normally, biological tissues scatter light due to their diverse composition of proteins, fats, and liquids. Researchers found that a concentrated tartrazine solution can match the refractive indices of these components, reducing light scattering and allowing light to pass through. This makes the skin appear transparent.
When applied, tartrazine absorbs certain wavelengths of light, especially red light, changing how light interacts with the tissue. This effect enabled the researchers to see blood vessels, internal organs, and muscle contractions in real-time. Importantly, the process is reversible; rinsing off the dye restores the skin's original appearance.
Experimental Findings
Initial tests involved applying the dye to chicken breast slices, which became transparent to red light. Subsequent experiments on live mice showed that the dye made the skin on the skulls and abdomens transparent. This allowed researchers to visualize blood flow, organs such as the liver and intestines, and even physiological processes like heartbeats and respiratory movements. The dye caused minimal inflammation and no long-term health effects were observed.
