Maceration (bone)

Maceration is a bone preparation technique whereby parts of a vertebrate corpse are left to rot inside a closed container at near-constant temperature, to get a clean skeleton. It is a form of controlled putrefaction, the decomposition of a corpse by bacteria in anaerobic conditions. The temperature is best maintained in an incubator at around 35 degrees Celsius. Maceration smells horrible, and the process should be done in a closed container, in a non-enclosed area.

Maceration is an alternative to the Dermestes method in which skin beetles are used to strip the flesh off of the corpse. Dermestes is advised for small mammals, small birds, reptiles, and amphibians, because these animals' bones tend to fall apart in many tiny parts. Maceration is nearly always the best and cheapest method when cleaning a single skull. Fish should not be macerated, because of their poorly articulated, pliable skeleton.

The corpse first needs to be skinned and defleshed as much as possible. All internal organs must be removed. In the case of mammals, care needs to be taken when removing the eyeballs, ears and jugular muscles, because some bones are shallow and brittle, for instance the thickened external acoustic opening of many mammals. The tongue should not be cut, because of the tongue and hyoid bones. A good tip is keeping the severed animal remains in several nylon panty hoses, for the legs, for the head etc.. Lipids and fatty acids in the bone and in the fat tissues tend to stain the bone brown.

The process itself is very simple. Put water (not warmer than 50 °C) in a bucket, optionally add some washing powder with enzymes (like Biotex), as it will soften the tissue (but take care with nails, as these are softened). A mild detergent or emulsifier can be used to remove fatty acids from the bone. Put the animal remains in the bucket, and close the lid. Bacteria will automatically start converting the flesh to their nutrients, and will continue to do so as long as the temperature remains constant. After two days the water needs to be replenished partially, to maintain the bacteria. This is a good time to further cut away flesh if needed. If left complete, most medium sized animals (like dogs) are macerated after ten days.

When done with macerating or using Dermestes beetles Biotex can be used again to whiten the bone, but care should be taken not to use too much, because the perchlorate can destroy the bone.