Going with the Flow

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.