stop sign with decomposition sticker - 'stop decomposition'
Plastination is a technique that stops decomposition and allows individual tissues and organs or whole bodies to be preserved.

Decomposition is a natural process triggered by cell enzymes released after death and later completed when putrification bacteria and other microorganisms colonize and further break down the body. Plastination removes water and fats from the body’s tissues and replaces them with plastic, depriving bacteria of the conditions they need to survive.

plastination diagram

The body is embalmed with formaldehyde, and then dissected. The water and fatty tissues in the body are replaced with acetone, a solvent that evaporates easily. Then the acetone is replaced with a polymer solution—a liquid plastic. To get the polymer into each and every cell, “a specimen is placed in a vacuum chamber and the pressure is reduced to the point where the [acetone] boils. The acetone is suctioned out of the tissue at the moment it vaporizes, and the resulting vacuum in the specimen causes the polymer solution to permeate the tissue.” The process can take a few days for thin slices, or weeks for entire bodies.

After each cell is infused with liquid plastic, the body is posed. Needles and pieces of foam rubber are used to hold muscles and nerves in place until the plastic is hardened.

posed plastinates
Specimens plastinated with silicone are cured with a special gas.

The Institute for Plastination uses several kinds of polymers, and each hardens under specific conditions—the presence of light, heat, or certain gases. The polymer chosen determines the look and feel of the specimen. (The posed specimens are infused with silicone rubber, which cures when exposed to a special gas.)

Preparing a whole-body plastinate takes 1000–1500 man-hours.