Technique of plastination



Thanks to the plastination technique, the interior of the body can now be depicted in more detail than ever before. The specimens remain dry, odourless and durable for an unlimited period of time. They are therefore invaluable for medical education, not only for aspiring doctors, but also for educating the general public.


First, the body is fixed, i.e. the process of decomposition in the body is halted by pumping a formalin solution into the body’s arterial system. After about three to four hours, all bacteria have been killed and the anatomical dissection can begin.

For this purpose, skin and subcutaneous fatty tissue are removed. Organs, muscles and tendons as well as nerves and vesselsare surrounded by a thin layer of fibrous connective tissue, which is carefully removed with the aid of tweezers, scalpels and scissors. The exposure of the anatomical structures requires not only anatomical knowledge and manual skill but also a lot of patience. Depending on the complexity, dissection takes 500 to 1000 working hours.


After dissection, the actual plastination process begins. In the first step, the body water, which makes up 70% of the human body, is replaced by a solvent, e.g. acetone. The specimen is placed in an ice-cold acetone bath, which gradually draws out the water in the body. The acetone bath is then heated to room temperature to dissolve the soluble fats from the tissue. The process of removing the water and fat takes about 3-4 months.


The next step is the central step of the plastination process. The acetone is exchanged with a reactive polymer, e.g. silicone rubber. This is done in a vacuum chamber filled with the liquid plastic. By creating a vacuum, the polymer in the specimen begins to boil. The acetone vaporising from the tissue is extracted, and the vacuum thus created in the specimen ensures that the plastic solution is drawn into every last cell. This process takes 2 to 5 weeks.


The silicon rubber impregnated specimen is initially still flexible and posable. The body is placed in the desired pose, each individual anatomical structure is correctly positioned and fixed in place with the help of wires, needles, clamps and other aids. Positioning requires great anatomical expertise, design skills and a sense of aesthetics. The whole process can take anywhere from a few weeks to several months.


In a final step, the silicon-impregnated specimen is hardened (cured) using a special gas. For this purpose, an airtight chamber is built around the specimen. Light or heat is used for other plastics, such as polyester and epoxy resins. With the hardening, the plastination process is completed and the plastinate is permanently protected from decay.