Diaphonized Creatures: The Artful Science of Diaphonization

You’ve likely seen diaphonized creatures on display in natural history museums, where transparent specimens of dead fish, frogs, and snakes float in crystalline vials. Unlike the stuffed birds and mounted deer heads of taxidermy, these specimens are transparent, offering a literal window into their skeletal structure—enhanced by the rich reds, purples, and blues that highlight their bones and cartilage. Scientists have been using diaphonization techniques for decades, but more recently, artists have also taken up the practice. Atlas Obscura decided to look a little deeper at this unique form of preparation.

First developed in 1977 by the scientists G. Dingerkus and L.D. Uhler, the process of diaphonization has also been known as “clearing and staining.” The animals are rendered transparent (the “clearing”) by bathing in a soup of trypsin, a digestive enzyme that slowly breaks down their flesh. They also soak in several batches of bone, muscle, or cartilage dyes (the “staining”), with alizarin red and alcian blue the most commonly used.

The results are at once visually striking and chemically intensive. As biologist Sadie Stednitz explained, “The appeal of diaphonized specimens is that they are beautiful physical objects that also give us an appreciation for biology.”

Stednitz is the owner of California-based Studio Pollex, which sells diaphonized pieces along with more familiar taxidermy. Stednitz told Atlas Obscura, “I work primarily with animals [that are] available as dissection specimens: rats, mice, frogs, fish, and snakes.” But not all creatures are suitable for the procedure, which has traditionally been used to study an animal’s skeletal structure. Large birds and mammals have feathers and fur that are difficult to remove. Moreover, both types of creatures are commonly dissected, and can easily be dry preserved.

Other factors are also important: “A large rat could take upwards of six months to complete, so time is a big consideration,” Stednitz said. “The denser and larger the tissues, the longer it will take for any stains to reach them. Anything that affects the chemistry of the dyes can [also] cause issues. For example, some dyes will only work in an acidic solution, and some animal tissues do not fare well in that kind of environment.”

Indeed, the technique is most often used with specimens that measure less than a foot in length. Thin-skinned amphibians, fish, and reptiles are especially well-suited to diaphonization, because their tissues are often too delicate for dissection and require preservation in fluids. Young mammals and birds are also suitable for this reason. By avoiding invasive measures, diaphonization helps scientists identify bones and cartilage structures as they exist in the body without any displacement. The technique is also especially useful for studying fetal organisms in the laboratory.

With a crystal-clear view of the subject’s internal features, scientists can also observe the direct impact of environmental pollutants. Diaphonist Brandon Ballengée has been a pioneer in this field, using cleared and stained frogs to highlight deformities such as extra limbs. Furthermore, fetuses offer crucial insight into how these chemicals affect normal growth and development.

As Stednitz notes, “Comparative anatomy is another application; if you want to visually demonstrate the evolutionary relationships between different species, the skeleton is a good place to start because it is easy to see how one body plan can be modified to suit many different tasks.”

Despite its merits, diaphonization is not widely used in the field, due to its finicky and time-consuming nature. Advancements in imaging technology have also rendered the practice uncommon. However, diaphonization is increasingly becoming an art form. Animals that are predominantly cartilaginous, such as rays and sharks, will appear blue due to the cartilage stain, while bony fish, mammals, and reptiles will appear mostly red from the bone stain. Shades of purple can even be seen with muscle stains. With such a variety of vivid stains and animals to choose from, the creative possibilities are endless.

Among the public, diaphonization is not well known aside from a handful of collectors who seek out curios. Thankfully, that trend is slowly changing with the presence of Studio Pollex, and the exposure of other diaphonists such as Iori Tomita and Dr. Adam Summers. Tomita’s work has been displayed around Japan, including at the Tokyo Mineral Show, while Dr. Summers was featured in an exhibit called “Cleared: The Art of Science” at the Seattle Aquarium, which opened on December 1, 2013 and will be on display until early June (it will then go on tour).

Fortunately, these magnificent works of anatomy can also be found in several natural museums. Often, the cleared and stained specimens are housed within ichthyology (fish) or herpetology (reptiles and amphibians) collections. Some notable locales include the Field Museum of Natural History, Royal British Columbia Museum, Texas Natural Science Center, Yale Peabody Museum of Natural History, Burke Museum of Natural History and Culture, Carnegie Museum of Natural History, and University of Alberta’s Museum of Zoology.

But no matter the location, the sight of a diaphonized animal is instantly appealing. Stednitz sums it up best by saying, “Visibility, color, and presentation are important factors for both academic and artistic specimens.” Indeed, the process of diaphonization blends art and science together so skillfully, it revives the dead with new life and color.

Many of these locations serve as repositories for research. For example, the Carnegie Museum of Natural History boasts one of the largest herpetology collections in the United States. The Burke Museum has an ichthyology collection that has 324 lots of cleared and stained fish. The Field Museum of Natural History has an online searchable database of diaphonized fish, which lists the international location of specimens.

Diaphonized specimen by Sadie Stednitz, image copyright Chad Lowe