You might find yourself enthralled by the dazzling pink and blue 3D specimens of rays, seahorses, and sharks that grace natural history museums—and some online slideshows. Now, a new improvement to an old imaging technique promises to reveal even more details in vertebrates, with scans that might be as at home in the art gallery as in the lab.
Biologists have been deciphering the anatomical details of bony animals for about 50 years using a technique called clearing and staining. Scientists take small fish, amphibians, reptiles, and mammals and dip them in baths that make the flesh transparent. Several more baths dye their cartilage bright blue and their bones bright red, allowing for a dazzling display of anatomical detail.
However, some detail still gets lost. To enhance their images, researchers took a “snapshot” of their specimens by shining specific wavelengths of light on the dyed bones and then filtering out all colors except red or green. When scientists added their filter, the details in the skeleton popped like never before, researchers report in the September issue of Copeia. The resulting image—in which the bones are still red, but the soft tissues are green—makes it much easier for scientists to differentiate between tissues. The technique might even be useful for imaging fossils because scientists could use it to “delete” the surrounding rock from scans to focus on the ancient bones.
Another improvement: Scientists figured out a way of getting the specimens, floppy 3D models that need to be mounted for imaging, to sit up straight. By adding a little gelatin to a 40% glycerin solution in water, they had just enough time to pose their creatures before they hardened into place—ready for their next glamour shot.