Now you see it, now you don’t: Scientists have used a chemical technique to make mouse bones turn transparent. The technique has been used in the past to make brains and kidneys see-through, but this marks the first time it’s been used in hard tissues.
The ability to see within a bone could have implications for research into bone diseases, by letting researchers get a more accurate picture of bone’s internal structure.
The technique is called CLARITY, and since 2013, when it was first described, it has been deployed on a wide variety of mammalian tissues and in plants. Caltech neuroscientist Viviana Gradinaru, an original developer of the technique, even cleared an entire mouse’s body in 2014 (except for its bones, which were unaffected, she said).
The approach works by chemically locking proteins and DNA in place with a hydrogel, after which researchers wash away fats within the tissue. Lipids refract light, so this washing step makes CLARITY-treated tissues transparent.
In this case, Gradinaru wanted to look at bone marrow and count the number of stem cells that could ultimately produce new bone cells.
“Bone is not a static organ. It is continuously changed. The bones we have in our body, we didn’t have them 10 years ago,” she explained. A continuous process of bone cell death and bone cell growth is happening, spurred by progenitor cells in a bone’s soft, spongy marrow.
Image Credit: Alex Hogan/STAT