Everything You Need to Know About Wet Specimens

Wet specimens are more often than not synonymous with biological education specimens. They’re also called “preserved specimens” and sold in jars for dissection, lab display, or research purposes.

Wet specimens can be whole animals or their specific organs (heart, brain, kidneys, etc.), as larger animals are seldom dissected in their entirety. Click here to browse preserved wet specimens. As you may notice, not all of these specimens are preserved in jars. However, we’ll solely focus on those embalmed and stored in a permanent liquid solution.

Understanding how these specimens are made is the first step towards fully understanding them.

The Making of a Wet Specimen

Most but not all preserved specimens at Blades Biological Ltd. are injected with and submerged in a preservative containing large amounts of ethanol or formalin. After taking the specimen out of the solution, submerge it in distilled water for a day or two to remove any excess solution.

After the formalin or ethanol solution has been sufficiently leeched out of the specimen, we transfer it to a jar containing 70% isopropyl alcohol or ethanol. The transfer process is slightly longer for delicate species, requiring us to increase the alcohol or ethanol content slowly to avoid wrinkling.

When making wet specimens, be sure to wear proper PPE, especially when using formalin, a carcinogen known for causing nasopharyngeal and blood cancer.

Understanding Wet Specimens from their Murky Origins

Looking back at the history of wet specimens and comparing them with the fluid-preserved samples we see now can help you make a comparison and learn why these methods had to evolve.

The embalming and preservation process wasn’t perfect, but it had to start somewhere. In this case, it all started with Frederik Ruysch.

Frederik Ruysch and His Quest to Make Specimens Last Longer

Frederik Ruysch was the pioneer of embalming. He became a known anatomist in the 1600s after realizing the need to preserve human bodies, as they were notoriously difficult to procure through legal channels.

The Dutch physician had to advance his knowledge of human anatomy through dissection. However, he quickly realized that there was only so much he could learn from a single cadaver before it started to decay.

Liquor Balsamicum: The First Alcohol-based Preservative

Liquor balsamicum was the first-ever alcohol-based preservative created by Ruysch to preserve specimens. He took several decades to develop the solution, which had more than just alcohol. Other notable (and bizarre) ingredients were revealed in 2006 and included:

Mercuric sulphide
Mercury oxide
Berlin blue
Pig’s blood

While this solution worked to preserve the specimens, students could only work on them during the winter because the rancid smells of bacteria emanating from the cadavers during the warmer months would be too potent for humans, even anatomy students, to stomach.

The Legacy of Frederik Ruysch

By the time Ruysch passed, he had used his embalming solution to teach students about human anatomy and train midwives in birthing babies and caring for mothers and their babies.

The Dutch physician also had a museum, something he had started at the tender age of 24, that housed wet specimens, mummified organs, foetuses, and skeletons. His daughter made the macabre displays at the museum look palatable by adorning them with flowers, shells, and other bric-a-brac.

Unfortunately, this part of Ruysch’s legacy wouldn’t last. He sold this collection, his anatomy research, and the recipe for liquor balsamicum to Peter the Great in 1717.

Centuries Later: Fluid-Preserved SpecimensReign Supreme

Almost every educational institution, museum, and research lab maintains a collection of fluid-preserved, aka wet specimens. Students don’t usually get the animals or organs they’re about to dissect in the glass jars mentioned above.

However, their specimens wouldn’t be this intact or fresh without being treated with an alcohol-based preservative.

While you get specimens on a tray at schools, you may see them in jars at museums. These places don’t refer to their preserved specimen collections as “wet specimens”. They may call them “ethanol collections” or something similar. The Natural History Museum just so happens to call their preserved specimens the “spirit collection”.

Since these specimens are highly flammable, you might have to do a bit of searching to find them. Limit your search to fireproof rooms; they usually have heavier doors.

The Scientific Value of Wet Specimen Collections

Paleoart recreations are only as accurate as the skeletal remains allow them to be. Just look at dinosaurs; we take their paleoart reconstructions at face value, but we’ll never know what they looked like because a) we didn’t exist, and b) even if we did, we probably wouldn’t have a way of preserving their cadavers.

The point of saying this is that every specimen has scientific value. Ethanol or formalin solutions let us immortalize specimens across the ages, so researchers can come back to them in the years to come even after they’ve become extinct and carry out DNA sequencing, which may, in turn, enable them to clone extinct species further down the line and reintroduce them to the wild.

Understanding wet specimens is understanding life itself. It makes learning a highly immersive process and teaches us about long-forgotten and endangered animals. The latter is particularly important because it helps us create a safer ecosystem for these animals, so they can thrive and regrow their population.

Find All the Preserved Specimens You Need Online

Blades Biological Ltdcurates preserved and frozen specimens and the biological equipment to dissect them. Get new dissection equipment for your school lab, replenish your supplies, and place a bulk order for wet specimens for an upcoming dissection session. We curate small animals and individual organs as well.