Редактирование: Cryonics alternatives (раздел)

== Freeze Drying ==

Freeze drying, also known as Lyophilization; consists of freezing tissue, then reducing the atmospheric pressure and applying heat to sublimate the water ice in it. A freeze drying machine is a large chamber of heated shelves. Its atmosphere is connected to a vacuum pump and exposed to refrigeration coils.

In the process, the solid is first frozen; creating damaging ice crystals. The vacuum pump lowers the pressure to .6 ATM; ten, the shelves are heated, and due to the low pressure, the ice sublimates directly. This process can take several days (A single (.1386Kg) human brain took 28 to freeze dry. Slicing it, however, reduced the time to 14 days.<ref>Freeze-Drying Biological Specimens: A Laboratory Manual</ref>).

The material, at least in the case of food, can be preserved for several years without decay.

The main advantages of Lyophilization are that the removal of water and oxygen from tissue will reduce decay, and that it does not require expensive equipment or maintenance. A secure container, however, must be obtained and inspected to ensure that Oxygen does not enter the tissues.

The reduced dependence on equipment increases the safety of the storage and reduces the vulnerability of the tissue. There is some overlap in the storage advantages (Namely very low cost and easy storage) of Plastination. Moreover, freeze-dried material can be cryogenically stored later on.

In terms of cost, a single Lyophilization machine, the Taxi-Dry runs at 'less than a dollar a day', and most machines capable of fitting a human brain, head or body cost above $10,000, significantly cheaper than the cheapest perfusion machine.

The most obvious disadvantage is the the Lyophilization process is very destructive it itself. Since freezing happens before dehydration, ice crystals form. When they sublimate, the structural integrity of the tissue is compromised, due to the pores this leaves behind. This might be a solvable problem, but for now, the process is more destructive than the standard Vitrification protocol. Freeze drying also leaves 2% moisture, reducing the storage time to mere years.