Researchers improved on a technique called stimulated Raman spectroscopy to capture real-time images in the skin of living mice. To observe the absorption of trans-retinol, a common skin-care product, into a mouse’s skin, the team tuned two lasers to the frequency of a lipid in the drug and trained the lasers on the application site, yielding images in real time of the drug traveling down a hair shaft into the sebaceous gland.
Using stimulated Raman spectroscopy, researchers tuned lasers to the frequency of proteins in red blood cells. They trained the lasers on blood vessels in the ear of a mouse. A detector captured the resulting protein signals, translating them into images, which researchers sequenced together to create a video of red blood cells flowing through the capillaries of a mouse. The movie shows a Y-shaped junction of blood capillaries with individual red blood cells.