Anyone (old like me) remember the Visible Man and Visible Woman models? Maybe they weren't as far fetched as you might think...

Anyway, the substance is a common food dye: the one that gives Doritos their orange color...and the skin is on a mouse. Then, using light of a certain frequency, you can see through the skin to the underlying structures. 

There is a depth limitation of a few millimeters, but still...this opens up avenues for further research. Imagine Doctors could image internal structures without harmful radio-opaque dyes or radiation...and actually see blood coursing, etc. The future looks to be a cool place, if we don't eliminate the human race.

Take a look at the linked article. I can't reproduce the image there legally without paying, so...you'll have to click to see the laser speckle image. However, here's a video of the dye technique and results from The Guardian:

(credit The Guardian)

This is rather amazing, but honestly it hasn't been tested in people yet so please don't go and ruin your clothing and develop allergic rashes, etc. I don't want a bunch of irate mommies hunting me down because their kids are now yellow as are their clothing, etc.    

Links:

1. https://www.theguardian.com/science/article/2024/sep/05/common-food-dye-found-to-make-skin-and-muscle-temporarily-transparent

2. https://www.nature.com/articles/d41586-024-02887-4?utm_source=Live+Audience&utm_campaign=5768ff8509-nature-briefing-daily-20240906&utm_medium=email&utm_term=0_b27a691814-5768ff8509-49361556