The Basics

"Decay is a vital process in nature but an impediment to morphological studies, teaching, and research [not to mention survival!]. Plastination is a unique method of preserving tissue in a lifelike state. Plastinated specimens are dry, odorless, durable, last indefinitely, and can literally be grasped. They even retain their original surface relief and cellular identity down to the microscopic level.

Generally, the plastination process consists of four steps: fixation (for which any conventional method can be employed), dehydration, defatting, and plastination. After fixation, the specimen is put in up to three bathes of -25°C cold acetone for dehydration purposes. After dehydration it is put in acetone at room temperature for defatting.

Forced Impregnation is the central step of plastination: The specimen, soaked with the volatile solvent, is placed into a polymer solution. When vacuum is applied, the intermediary solvent is continuously extracted in its gaseous state. The evaporating acetone creates a volume deficit within the specimen drawing the polymer into the tissue as its replacement.

The preservation of thin body and organ slices (= Sheet Plastination) is more complex and requires significant investment in both equipment and auxiliaries. Organs are cut with a meat slicer, body specimens containing bone structure are cut with a band saw in 2-8 mm thick slices.

After impregnation the slices are cured between foils or glass plates or are casted with additional resin in a flat chamber composed of glass plates. Transparent body slices allow for detailed studies on anatomical and pathological structures in their topographical context.

Plastination was invented at Heidelberg University by Dr. med. Günter von Hagens back in 1978; ever since then, many applications have been derived from this unique process (Note: Dr. von Hagens has since set up the Institut für Plastination in Heidelberg, Germany, which also accepts "body donations" from the general public. A body donation to the Institute might in fact be one of the cheapest ways to have yourself preserved -- more on that below). Plastination is carried out in many institutions worldwide and has obtained great acceptance particularly because of the durability, and the high teaching value plastinated specimens have."
[Source: Preservation by Plastination, by Samuel P Klaus]

Though obviously this should be of some interest to all serious life extensionists and cryonicists, especially those on a tight budget, I could hardly find any useful/relevant info on the various cryonics websites (this one being the most notable exception), or even in the CryoNet archives. Very strange indeed...Surely, such a potentially (very) cheap and convenient preservation technique deserves a proper evaluation (other potentially useful low-budget cryonics alternatives like permafrost burial and "super" embalming, for example, have been, and occasionally still are, given serious consideration by at least some cryonicists). Cryonics organizations state that they may use "chemical preservation" (possibly in combination with permafrost burial) as an emergency back-up, but this doesn't seem to include plastination; at least there's no explicit mention of it on their websites. Below is a rudimentary comparison of cryonics and plastination, as well as some tips and comments. It may not be much, but at least it's a start. Watch this space for more info!

Advantages of Plastination:

• Extremely safe, cheap and easy storage, certainly when compared to liquid nitrogen storage, which can easily cost several thousand EUR / USD a year and requires a certain level of expertise due to its potentially dangerous (asphyxiation, freezer burn, even explosions if the dewar is perforated all the way to the vacuum chamber) nature. A plastinated brain could be stored just about anywhere (though preferably in a cool, dark place to minimize tissue & polymer deterioration). Also, one would expect fewer legal hassles with the storage of plastinated specimens than with cryonics (and should there be some legal trouble after all, a plastinated brain would be much easier to hide from homicidal bureaucrats than a frozen one).
  
• Potentially available for FREE (body donation) -or at least for much less than cryonics- to just about anyone in Europe (and possibly the US as well).
• Plastinated brains could always be transferred to cryogenic storage (electrical or LN2) at some later date, when the financial situation and/or local infrastructure allows. In other words, plastination could be used to buy the friends and/or family members of the deceased some (a lot of?) extra time to make proper cryonic storage arrangements.
  
  Potential Disadvantages of Plastination:
  
• At room temperature, there might still be some (slow?) decay, regardless of the vacuum, chemical fixation, dehydration & defatting. Cooling in a regular freezer (not too expensive) or even permafrost burial, for example, could significantly slow decomposition, however. Mild or medium-level cooling & plastination could be a strong combo indeed, though cryogenic storage would obviously be even better. Assuming that plastination alone already significantly slows down decomposition, a power failure/technical malfunction would be no big deal, and in any case there could be no Chatsworth disasters.
  
• The process itself might cause "irreversible" information loss in the brain (but then again, so could cryonics). At the moment this is simply unknown, but trying to preserve as much as one can is always the logical and ethical thing to do.

The Basics

The fundamental principle in freeze-drying (also known as lyophilization), is sublimation, the shift from a solid directly into a gas. Just like evaporation, sublimation occurs when a molecule gains enough energy to break free from the molecules around it. Water will sublime from a solid (ice) to a gas (vapor) when the molecules have enough energy to break free but the conditions aren't right for a liquid to form.

There are two major factors that determine what phase (solid, liquid or gas) a substance will take: heat and atmospheric pressure. For a substance to take any particular phase, the temperature and pressure must be within a certain range. Without these conditions, that phase of the substance can't exist.

Water can take a liquid form at sea level (where pressure is equal to 1 atm) if the temperature is in between the sea level freezing point (32 degrees Fahrenheit or 0 degrees Celsius) and the sea level boiling point (212 F or 100 C). But if you increase the temperature above 32 F while keeping the atmospheric pressure below .06 atmospheres (ATM), the water is warm enough to thaw, but there isn't enough pressure for a liquid to form. It becomes a gas.

This is exactly what a freeze-drying machine does. A typical machine consists of a freeze-drying chamber with several shelves attached to heating units, a freezing coil connected to a refrigerator compressor, and a vacuum pump. With most machines, you place the material to be preserved onto the shelves when it is still unfrozen. When you seal the chamber and begin the process, the machine runs the compressors to lower the temperature in the chamber. The material is frozen solid, which separates the water from everything around it, on a molecular level, even though the water is still present.

Next, the machine turns on the vacuum pump to force air out of the chamber, lowering the atmospheric pressure below .06 ATM. The heating units apply a small amount of heat to the shelves, causing the ice to change phase. Since the pressure is so low, the ice turns directly into water vapor. The water vapor flows out of the freeze-drying chamber, past the freezing coil. The water vapor condenses onto the freezing coil in solid ice form, in the same way water condenses as frost on a cold day. (See How Refrigerators Work for more information on condensers and refrigeration coils.)

This continues for many hours (even days) while the material gradually dries out. The process takes so long because overheating the material can significantly change the composition and structure. Additionally, accelerating the sublimation process could produce more water vapor in a period of time then the pumping system can remove from the chamber. This could rehydrate the material somewhat, degrading its quality.

Once the material is dried sufficiently, it's sealed in a moisture-free package, often with an oxygen-absorbing material. As long as the package is secure, the material can sit on a shelf for years and years without degrading (note: this applies to food; a more thorougly (pre-)treated animal or human specimen could last much longer). [...] If everything works correctly, the material will go through the entire process almost completely unscathed!
[Source: How Freeze-Drying Works, by Tom Harris]

Some Meditations on Lyophilisation

by Douglas Skrecky

It was with great interest that I read Yvan Bozzonetti's recent [CryoNet] article examining freeze drying as a possible affordable alternative to cryonics. I too have been thinking along similar lines for some time and I would like to share some of my thoughts on this topic.

The reason cryonics companies use liquid nitrogen is because of the requirement that devitrification be avoided. This process occurs whenever temperatures rise above about -86 degrees celsius since ice crystals can then begin to grow and mechanically destroy tissue structure. Even chemically preserved tissue would be destroyed by this process. Other problems that the low temperature of liquid nitrogen suspension addresses are preventing frozen tissue from suffering from other water and oxygen dependant deteriorative processes such as hydrolysis and oxidation. A key insight is that by eliminating both the water and oxygen from tissue you thereby eliminate the need for temperature reduction!

However cryonicists might still wish to argue against freeze drying on the grounds that it is too destructive of tissue structure for reanimation of preserved remains ever to be practical. Freeze dried food for instance tends to suffer from a "woody" texture which is due to ice crystal growth during the process of freeze drying. Such food also fails to hydrate completely when it is used due to the extensive denaturation of tissue proteins which occurs during the drying process. To make matters even worse such foods tend to deteriorate after a few years because freeze drying still leaves about 2% moisture. There also may be structural deterioration stemming from the fact that freeze dried food is porous due to the presence of voids left by the ice crystals.

However all of these technical problems can be solved. Common table sugar both inhibits ice crystal growth in frozen foods as well as prevents denaturation of proteins when they are dried. It is the presence of sugars that enables both seeds as well as certain animal organisms such as brine shrimp and nematodes to survive complete desiccation - a phenomena which is called anhydrobiosis. Most of the moisture remaining in freeze dried tissue can be removed by heating the tissue while it remains under a vacuum. The tissue is then stored in a oxygen and water proof container which is packed with ample quantities of a desiccant such as calcium oxide. The structural weakness associated with porosity can be reduced by treating the tissue with sugar as well as chemical fixatives such as formaldehyde and glutaraldehyde just before freezing. The voids could even be filled with a low temperature thermosetting polymer such as glycol methacrylate. However even after admitting that the technical problems can be overcome cryonicists can still point to the one great remaining weakness of freeze drying.

It is still expensive. The porous nature of the tissue which is desiccated by this method acts as a vapour barrier which makes treatment of large animals such as humans much more expensive than for small pets. Preliminary estimates for the price tag associated with freeze drying a human are around 20 thousand U.S. dollars. [Note: this may or may not be true, but freeze drying and subsequently storing just a head or brain should be a lot cheaper, in any case. See also the "pro & con" section below]. While cryonic companies may wish to expand their product lines with a freeze drying option at some point in the future this development will be of little benefit to the would be immortalist of modest means who has no wish to impoverish his/her widow/widower.

However a person even in this financial category still has some alternatives to extinction. If bodily tissues are treated with sugars as well as high dosages of chemical fixatives shortly after death the "patient" could be air dried to produce a high quality mummy at very little expense. An intermediate cost alternative would be to replace the chemical fixatives with calcium chelators and antioxidants to halt autolysis as well oxidation while the body is mummified under a vacuum at close to freezing temperatures. By perfusing with an antifreeze based solution such mummification could even be carried out at the same low temperatures traditionally used in freeze drying.

The least expensive storage medium is a stainless steel casket buried in a cemetery. Less expensive materials such as aluminum suffer from pitting and crevice corrosion from ground water which is either acidic, alkaline or containing dissolved metal ions. Stainless steel may still corrode if the ground water contains high levels of dissolved chlorides so even with this material one has to pick a cemetery located on high ground, well away from the sea shore. The most corrosion resistant grades of stainless steel contain at least 25% chromium and 3% molybdenum. If the budget allows a titanium casket might be considered which if buried in the arctic permafrost should keep a stored mummy safe for tens of thousands of years.
[Source: Longevity Report 29 Volume 3 no 29. First published October 1991]

Brain Freeze-Drying as an Economical Alternative

by Douglas Skrecky

Freeze-drying a brain should reduce storage costs quite significantly since liquid nitrogen cryostats would no longer be needed for storage. How much would it cost to freeze-dry a brain? Probably not very much as the following information shows.

In his book Freeze-Drying Biological Specimens: A Laboratory Manual Rolland O. Hower from the Smithsonian Institution details his experiences in freeze-drying a wide variety of biological specimens. Freeze-drying of a formalin fixed 1386 gram human brain took just 28 days at -30 C. Weight loss was 1145 grams or 83%. Slicing the brain reduced drying time to 14 days. Increasing the storage temperature to -5 C reduced drying time of an intact brain to 7 days, though numerous cracks were evident.

Considering its size the human brain seems to be remarkablely quick and easy to freeze-dry. A barred owl weighing 1369 grams took 130 days to freeze-dry at -20 C. A tortoise took 132 days, while an alligator took 9 months at -20 C. The absence of either a thick epidermis or bone which can act as vapour barriers may be the reason why the human brain was so quick to dry. [Source: CryoNet archives]

Freeze-drying at the Cryonics Institute?

From: Ettinger@aol.com
Date: Wed, 19 May 1999
Subject: freeze-drying; evolution of consciousness
Posted to: CryoNet

Dr. Henry Hirsch is interested in pursuing research in freeze-drying. This is one of the projects on the Cryonics Institute research agenda, but it is not yet near the top of the priority list.

Potential advantages of freeze-drying include economy of storage because of higher storage temperature, plus corresponding safety because of reduced vulnerability to interruptions of energy or liquid nitrogen supplies. There is also the possibility of combining freeze-drying with chemical fixation, increasing both of the above-mentioned potential advantages.

The main disadvantage--of either freeze-drying or chemical fixation, or a combination--of course is just the fact that viability (as currently observed or measured) is virtually nil at the level of mammalian tissues, in the context of current capabilities. This may be more of a psychological problem than a scientific problem, in the context of future technology. Logically, a sufficient degree of preservation of structure is all that is necessary, with preservation of function pretty much irrelevant--but that is a hard sell indeed, even to most committed cryonicists.

Another possible disadvantage might be cost of preparation. Freeze-drying something as large as a human, by any currently used methods, is a very slow process, and therefore an expensive one. We have some ideas to offset this, but so far we cannot see our way to giving this project a high priority. A higher level of research donations could change this.

Robert Ettinger
Cryonics Institute
Immortalist Society
http://www.cryonics.org
[Source: CryoNet archives]

Freeze Dry Specialties, Inc's Taxi-Dry ARA 1800 machine, at $10,995 a piece one of the cheapest on the market. It is a modular design (see picture below), and "expansion units" --treatment chambers minus the vapor trap and vacuum pump-- cost $5,995 per unit. Note how one could easily fit a brain, or maybe even a whole head, into the vacuum chamber. Using mostly off-the-shelf components, anyone with some basic technical skills (certainly Alcor's or CI's tech people) should be able to build a customized, larger version. After all, as someone put it, the Taxi-Dry is "basically a bastardized Frigidaire freezer." A large horizontal (as opposed to the pictured upright) freezer could be the basis for a whole-body preservation system for both larger pets and humans. Still, for brain & small pet preservation it might be preferable to buy a professional machine (i.e. the ARA 1800), which is an efficient, proven design. At least that way one can be reasonably sure that the thing will actually work.

Advantages of Freeze-Drying:

[Note: these are largely the same as with plastination]. Relatively safe, cheap and easy storage, certainly when compared to liquid nitrogen storage, which can easily cost several thousand EUR a year and requires a certain level of expertise due to its potentially dangerous (asphyxiation, freezer burn, even explosions if the dewar is perforated all the way to the vacuum chamber) nature. A freeze dried head or brain could be put in an oxygen- and water proof container which is packed with ample quantities of a desiccant such as calcium oxide. Alternatively and preferably, it would first be encased in a block of copal or durable polyester resin. The container could then be placed in a normal household freezer. In an emergency it could easily be evacuated / relocated just about anywhere by car etc. During the evacuation the container could be kept at room temperature without fear of any (significant) damage to the specimen.

1) Potentially much cheaper than even the most low-budget cryonics service. According to the manufacturer's website, [Taxi-Dry] "is a reliable and predictable system which operates quietly on 110 Volt current for less than a dollar per day." Ok, let's assume that this a bit too optimistic, and that the actual energy consumption is somewhere around 2-3 USD/EUR a day (depending on the local electricity costs, ambient temperature etc.) Let's say that it takes 1-2 months to freeze dry an "average" human brain. This gives us 2 x 30 = 60 USD/EUR at the low(er) end, and 3 x 60 = 180 USD/EUR at the high(er) end. Even if the actual electricity costs were to be 10 times higher, which seems rather unlikely, the procedure would still be very affordable.

Now, of course there would be some additional costs, namely a) transportation to the freezedry facility, b) treatment with various stabilizing chemicals, as mentioned in Mr. Skrecky's article [actually, embalming fluid might be a pretty good fixative; the perfusion could be performed by a local mortician and would presumably costs between $250 and $1,000], c) the water- & oxygen proof (metal, plastic?) container, and d) an "open-ended" electricity supply for the storage freezer (assuming one doesn't opt for permafrost burial instead), and the periodic (say, every 10 years or so) purchase of a new unit. Last but not least there's e) the cost of the freeze dry apparatus ($10,995 + transportation/delivery costs, approx. $1,000 if the unit has to be shipped to Europe, though it may be (significantly?) less if one is constructed DIY-style, on-site, using readily available components), which will somehow have to be incorporated into the overall pricing.

So, what would be the final price tag? This depends on a lot of factors, obviously. For example: Will the service be provided by a "professional" (cryonics?) organization, or will it be done by a more informal mutual aid group, i.e. a group of low-budget immortalists who collectively buy and/or build the necessary equipment, chemicals etc.? Will there be sufficient interest to ensure a certain (modest) economies of scale effect, or will freeze drying be even less popular than cryonics? How many, if any, freeze drying outfits will there be in Europe (obviously, if there's one relatively nearby, well within car/train range, this will significantly reduce transportation costs. If patients will have to be treated and/or stored in the US or some other remote place, the added transportation costs could effectively make the other cost-cutting advantages insignificant and pointless for non-Americans)? Freeze drying pets and other animals, used purely as a convenient taxidermy alternative, seems to be becoming quite a lucrative business in the US, with more and more taxidermists switching to this in many ways superior technique. Presumably, those who'd use freeze drying for human preservation could earn a few bucks on the side doing pet treatments, both "regular" ones and those focused on brain preservation. Is there a significant market in Europe for aesthetic pet preservations? Would it be possible to get a decent yet cheap container to store the specimens in? Etc., etc. All things considered, especially the relatively low cost of key equipment and the presumably neglegible maintenance costs (electricity for a regular household freezer, which tend to be very energy-efficient these days), it seems reasonable to assume that the procedure, if performed head/brain-only by non-profit, resourceful immortalists, should be no more expensive than a standard burial, or maybe even a cheap burial (i.e. approx. 2,000 - 5,000 EUR). 1,000 EUR (or even cheaper, like 500 EUR) deals might even be offered in some cases without significantly endangering the operation. While one probably shouldn't expect to get rich from the freeze-drying "business", it might very well be possible to create a self-sustaining operation, certainly when additional freeze drying services (such as aesthetic pet & plant preservation, see for ex. Freeze Dry Specialties, Inc.'s homepage for some more options) are offered.

2) Freeze-dried brains could supposedly be transferred to cryogenic storage (electrical or LN2) at some later date, when the financial situation and/or local infrastructure allows. In other words, freeze drying could be a very useful way of buying friends & family of a deceased person some (a lot of?) extra time to make proper cryonics arrangements.

Potential Disadvantages of Freeze-Drying:

1) Specimens, even if they're properly perfused and sealed in a container and cooled to -20/30*C, might be subject to significant structural deterioration, eventually (months, years). Still, even if this were the case freeze drying could, as has already been mentioned above, at least buy the "patient's" relatives or friends some time to raise the money for "proper" LN2 storage. Also, let's keep in mind that given the current rate of progress in key fields like computing, AI, bio- & nanotech, it probably won't be necessary to maintain the frozen for much longer than, say, 20-40 years. Beyond that point men will either become or create "gods", or blow themselves up. A freeze dried specimen (brain) may not last hundreds or thousands of years, but it's not unreasonable to expect that it will last at least a couple of decades.

2) The freeze drying process itself might cause "irreversible" information loss in the brain (but then again, so could cryonics, so it's a tie on this one).

Related links

• International Society of Lyophilization - Freeze Drying Inc. "The Society is a non-profit organization (registered in the State of Delaware in the United States) whose mission is to promote and advance the field of lyophilization (lyophilisation) by personal interaction using the Internet and supporting programs that provide financial and/or material assistance to those who need it. It is also dedicated to the promotion of friendship and understanding throughout the International Community by conducting meetings at various locations throughout the world."
  
  
• Freeze Dry Specialties, Inc. Manufacturers of (relatively) affordable freeze dry machines which could be used for both animal and human (brains, heads) preservation. In fact, these and similar units are already being used for pet preservation, albeit of the "old-fashioned", purely "aesthetic" kind. The cheapest model costs approx. $10,995. "Taxi-Dry is the right size at an affordable price [...]. It is a reliable and predictable system which operates quietly on 110 Volt current for less than a dollar per day."
  
  
• VirTis Another freeze dry machine manufacturer. Very high-tech, primarily geared towards the pharmaceutical / biotech / research crowd. Perhaps some of these models could be adapted for brain or pet preservation, but they won't come cheap. The VirTis site has a very comprehensive introduction to freeze drying, though.
  
  
• Freeze Dry Co. "Pioneering the floral freeze dry industry since 1978." Though intended for the treatment of flowers 'n' stuff, these huge machines might also be used for whole-body (or multi-brain) freeze drying.
  
  
• Pupsicles. Freeze-drying: It's not just for pets anymore, by Paul Demko. An article about Alan Anger and his "revolutionary" freeze dry machines, see also link above. At some point Anger mentiones that "at the University of Nevada's medical school the equipment is being used to preserve human brains without the carcinogenic addition of formaldehyde." Though no further details are given, this certainly looks promising from the (low-budget) cryonics perspective.
  
  
• Death Becomes Them Pet Preservation Is the Latest Thing in the Taxidermy World. "There's a new option available for pet owners who can't bear to say goodbye when their furry friends pass on: having them freeze-dried. " An article about Mike McCullough, freeze drying pioneer and owner of Mac's Taxidermy in Fort Loudon, Pa.
  
  
• Keep that pet frozen in time, for ever Another article about McCullough's pet preservation business.
  
  
• Pet Preservation Specialist "Pet preservation, freeze dry taxidermy services for cats, dogs and all family pets." Based in Colorado, USA.
  
  Note: As mentioned above, these kind of "pet preservation" outfits are essentially just glorified taxidermists; what you get is a (hopefully) good-looking freeze dried mummy. What happens to/with the animal's brain isn't quite clear, and will probably vary per service. Some might remove it (removal of the intestines seems to be a standard procedure, in any case), while others will freeze-dry it along with the rest (either per default or upon request). In the latter case this kind of service might be interesting for immortalist pet owners (see also the comments regarding the storage of freeze-dried specimens in the pet preservation section). American and Canadian pet owners, that is; there seem to be no such services available in good old thanatically backward Europe. Though this is probably due to a general lack of demand, there might still be a modest business opportunity here for enterprising immortalists. If a local group would decide to buy or build a freeze dryer for personal use (group members and their pets), it might as well offer "aesthetic" pet preservation services to the general public. Nothing to lose here, unless you're planning to preserve and store human remains without government approval, in which case it's essential to keep a low profile. If, on the other hand, publicity is what you want, you're bound to get it if you start a pet preservation business.
  
  
• Anthony Eddy's Wildlife Studio (AEWS) "The largest Freeze-dry service in North America, serving pet owners since 1989." Based in Missouri, USA.
  
  
• Perpetual Pet Pet Preservation through Freeze Dry Taxidermy. "We at Perpetual Pet are also animal lovers and pet owners. Retired from the ministry, we are a husband and wife team dedicated to making this difficult time easier for you. Not only can we provide careful, quality care for your pet but understanding, sympathy and care for you in your time of loss." Based in West Virginia, USA.
  
  
• Pet Preservation.Com A Canadian (Ontario) freeze-dry service.
  
  
• Thunder Bay Taxidermy "We are a full service, full time wholesale taxidermy shop, offering both conventional and freeze dry services and a very rapid turnaround time. We are your squirrel and pet specialists!" Based in Michigan, USA.
  
  
• Ross Freeze-Dry & Taxidermy "Ross Freeze-Dry & Taxidermy is dedicated to providing quality work at an affordable price. We offer quality freeze-dry work from exotic fish to pets in almost any pose you desire." Based in Mississippi, USA.
  
  
• Kulis Freeze Dry Taxidermy "Kulis Freeze Dry Taxidermy was established in 1968, and has grown into one of the largest taxidermy studios in the Midwest. Joe 'Kastaway' Kulis pioneered the use of freeze dryers in this industry, and has been using the process for at least the last twenty-five years." Based in Ohio, USA.
  
  
• Freeze-dried funerals environmentally friendly A somewhat strange article (scroll down) about a Swedish ecologist who is proposing "the ultimate in environmentally-friendly funerals": having your body freeze-dried and then shattered into dust to help fertilize the soil. From a cryonics-immortalist perspective, using a potentially life-saving technology to purposefully destroy a "dead" body is of course rather ironic, not to mention barbaric.
  
  
• For sale: Taxi-Dry Freeze Dryer This is one of Alan Anger's machines. It's a "double-barreled" (two 12 x 24 chambers), apparently second hand unit. Pricing: $8,800.
  
  
• Lyophilization - Introduction and Basic Principles, by Thomas A. Jennings, Ph.D. "The objective of this book is not only to provide an introduction to lyophilization but also review the underlying scientific principles upon which this subject is based."
  
  
• Vacuum freeze-drying, a method used to salvage water-damaged archival and library materials: a RAMP study with guidelines, prepared by John M. McCleary. Though primarily about the preservation of water-damaged books, this (fully online) book also has some interesting and useful general info regarding freeze & vacuum drying.
  
  DIY freeze drying-related papers & articles (quite old and probably not available online, though you never know). Source: Taxidermy.net forums.
  
  
• Meryman, H. T. 1960. The preparation of biological museum specimens by freeze-drying. Curator, 3(1):5-19. -
  The first substantial American paper on freeze drying whole vertebrates and invertebrates for display. A good discussion is given on the theory and machinery of freeze drying. The method for posing was to freeze the joints solid with liquid nitrogen (now generally replaced by a system of wires). A number of examples of freeze dried vertebrates and invertebrates are illustrated.
  
  
• Meryman, H. T. 1961. The preparation of biological museum specimens by freeze-drying. II. Instrumentation. Curator, 4(2):153-174. -
  Supplies much more technical information on the theory and practice of freeze drying as introduced in the previous paper. Contains graphs for drying times of various vertebrate groups and numerous tables on vapor pressure, drying times, insulation, vacuum pumps, etc. Thoroughly discusses the machinery necessary to create a functional freezer dryer.
  
  
• Harris, R. H. 1964. Vacuum dehydration and freeze drying of entire biological specimens. Annals and Magazine, Natural History Series 13, 7:65-74. -
  Presents a brief history of freeze drying and vacuum dehydration and describes two simple setups used experimentally at the British Museum (Natural History). Discusses results obtained in the study and theorizes improvements in the technique. A toad freeze dried for one year was later able to be relaxed, fixed, processed in traditional methods, and examined microscopically with good results.
  
  
• Hower, R. O. 1964. Freeze-drying biological specimens. Museum News Technical Supplement no. 1. 8 pp. -
  Semi-technical paper on freeze drying specimens. Hower gives a short history and description of the process and the individual components of a freeze drying unit, along with suggestions on how to make a small apparatus.
  
  
• Hower, R. O. 1967. The freeze-dry preservation of biological specimens. Smithsonian Institution, Proceedings of the United States National Museum, 119(3549):1-24. -
  Similar to the preceding paper only containing more technical data.
  
  
• Hower, R. O. 1970. Advances in freeze-dry preservation of biological specimens. Curator, 13(2):135-152. -
  This article was basically an update on the technology available at the time as well as a description of the progress made in freeze drying specimens for exhibit at the Smithsonian Institution. Contains a discussion of the problems of formaldehyde and also a report on freeze drying a water-soaked book from 1865.
  
  
• Hower, R. O. 1979. Freeze-drying biological specimens: a laboratory manual. Smithsonian Institution Press, Washington, DC. 196 pp. -
  The classic work for freeze drying specimens. R. Harris describes succinctly the history of freeze drying in the introduction. Hower then proceeds to cover thoroughly the theory, instrumentation, and technical information necessary to prepare scientific specimens by this process. Contains many illustrations of dried vertebrates and invertebrates which show the success of this system in creating reasonably good exhibit material. Includes directions for making glass eyes and an extensive bibliography on freeze drying.
  

Cryonics for Pets

It's freezing cats and dogs!

Apart from friends and family members, some people may also want to take their favorite pet(s) with them to the future. Technically and legally this isn't a problem; the standard cryonics protocol can be used on animals as well, and most bureaucratic barriers regarding euthanasia, transport & storage of remains etc. don't apply to pets so that, ironically, they can get a much better suspension than humans. The costs of a pet suspension, however, may be somewhat high for most people; $5,800 (Cryonics Institute) or $10,000 (Alcor), and this doesn't even include transportation costs to the cryonics facility. Taking into account that one probably has to use the services of a funeral director, these could be quite considerable, especially if you live outside the US (approx. EUR 7,000 - 10,000 (?) for humans, maybe it's a bit less for small animals, but that's by no means certain). Also, apparently this is a special service for Alcor/CI members only, not for the "general public", and only average-sized animals (cats or cat-sized dogs) are accepted at the above-mentioned prices; storage of larger animals could cost (almost) as much as human storage (i.e. $30,000 - 150,000!), assuming one can actually fit the animal into the cryostat/dewar. In other words, whole-body elephant suspensions are out of the question, though just about any animal's head or brain would presumably be ok, and its storage should even be available at the lower price since few pets' heads, and even fewer brains, will significantly exceed "cat size".

Perhaps there are cheaper ways to (privately) store pets privately; this is currently being investigated. Some -very crude and basic- suggestions have been listed below, ranked according to pricing and general feasibility, and more or less "reverse-ranked" by effectiveness (except for options #3 & #4). More details regarding these & other options, including detailed step-by-step protocols for DIY (pet) suspensions will be added as we go along.

General guidelines: when the animal dies and you're pretty sure you can have it either plastinated (option #2) or perfused and cryoprotected (by a cryonics organization) within a few days, it should be immediately cooled down to, and stored at, several degrees C above the freezing point (of water). For rapid cooldown, running ice-water is the method of choice. Click here for some practical tips. If you're going to try freeze drying (option #5) or cryogenic straight freezing (options #3 & 4), or simply aren't sure yet, you can put the animal in a regular freezer, highest setting. If you're going for alcohol storage (option #1), the animal should, after removal of the intestines (recommended for larger animals), be submersed in refrigerated alcohol a.s.a.p. If there's some kind of relatively short delay, the animal should be cooled but not frozen (yet).

Option #1: Alcohol. An old and widely used preservation method. Put the animal's head, brain, or entire body (after removal of the intestines; this could be done by a vet or other "professional", if you can't do it yourself) in a glass, stainless steel, or plastic container (a drum; usually this is the best option) filled "to the rim" with alcohol (70-90% purity) or methylated spirit. According to Doug Skrecky, some sodium chloride (i.e. common salt) could be added to better preserve the DNA. Glycerine (5%) can also be added to the mixture; supposedly this helps to protect the specimen should the alcohol accidentally be allowed to dry up/escape -- something which, obviously, should be avoided at all times. The container should then be sealed and stored in a dark and cool place, ideally in a freezer (maximum setting, if applicable). Putting large dogs and large(r) animals in general -which require relatively large and heavy storage vessels- into a regular household freezer might be a bit problematic, though; even if the drum fits (and obviously it would have to be filled with alcohol after it has been placed into the box), the freezer's bottom might not be able to take the weight (long-term), and get damaged.

The container should be inspected from time to time for leaks etc., though these are unlikely. Also, make sure that no part of the animal is sticking out, the lid is closed properly, the container is placed in a stable position, and that whatever it is resting on can easily take the weight. Add supporting structure if deemed necessary. The primary container can be placed inside a slightly larger secondary container for additional safety.

Tip: because body fluids will inevitably contaminate and dilute the alcohol during the first couple of weeks or months following immersion, it is recommended to fully refresh the vessel's contents at least once. This can be done after a few weeks, or as soon as the liquid starts looking cloudy or outright filthy. Ideally, the -pure- alcohol should be clear like Vodka. The glycerine, salt, and (possibly) other extras, which may or may not cloud the alcohol, should only be added after it has been refreshed.

Advantages: This is a very cheap, easy, and relatively low-maintenance method of preservation. Anyone can do it with off-the-shelf materials / gear, i.e. alcohol, a glass or plastic container, and a regular freezer (optional).

Disadvantages: Alcohol is a relatively poor preservative, at least from the cryonics perspective. Though biological specimens can be stored for many decades without any significant exterior degradation (Einstein's brain and the Tasmanian Tiger "clone pup" come to mind; the latter apparently "survived" 130 years or so of ethanol storage), it is said that under a microscope they look like "mush", even after just a few months [see for example this CryoNet message by Joseph J. Strout]. Unlike liquid nitrogen storage, alcohol or other chemical preservatives can only slow decay down somewhat, not stop it "entirely" (or rather slow it down to a pace where it becomes almost negligible). Refrigeration undoubtedly helps, but its effects are limited at normal freezer temperatures (approx. -20*C). Still, even poor preservation is better than the barbaric, willfully destructive alternatives, if only for moral reasons. Also, even what may today look like "mush" under a microscope could in fact contain a lot of useful information by future standards, maybe even enough for a near-perfect reconstruction -- certainly when combined with other data, such as video recordings, photos, writings, other people's (or animals') memories etc. It never hurts to try, in any case.

Another issue is the high flammability of "pure" alcohol. Handling will require due caution and common sense, i.e. keep the storage vessel well away from (potential) heat sources, make sure that it doesn't get damaged by sharp objects, regularly check for leaks, never handle it roughly etc. If you live in or near the Arctic region you might consider giving the container a permafrost burial.

Option #2: Plastination. Pet plastination is slightly easier than human plastination. There is at least one company that performs animal plastinations for private individuals: VisDocta Research in Italy. A dog brain costs approx. 1,100 EUR and a cat brain 800 EUR, "according to weight". The method used (and recommended) is whole-brain silicone impregnation, as opposed to slicing which is both more destructive and expensive. The pet's owner must present a "vet declaration" which states that the pet either died naturally or by means of euthanasia, and has no contagious disease. In most cases this will be just a formality; contact your local vet for more info. It is also recommended to contact VisDocta while your pet is still alive, to make sure that everything goes as smoothly as possible when the time comes.

Advantages: The procedure itself should be affordable to most (Western) pet owners. It's ultimately a matter of priorities; how much is the pet's (potential) survival / your own peace of mind worth to you? There should be relatively few legal restrictions regarding transportation & storage of plastinated animal specimens. Refrigeration (standard freezer) is recommended but not absolutely required, and in an emergency a plastinated brain would be very easy to evacuate; put it in some kind of box & off you go.

Disadvantages: Same technical uncertainties as with human plastination, but minus the added legal hassles. The further one lives from Italy, the more difficult (& expensive) it will be to get the pet's brain to the VisDocta facility (in time). Specimen retrieval / transportation can be taken care of by the company, but this will cost you approx. 1,000 EUR extra (could be more nowadays). However, even with these added costs this option is still much cheaper than having the pet shipped to the USA and frozen by either CI or Alcor (if you live in Europe, that is; for non-Europeans, VisDocta would be a fairly expensive option due to transportation costs).

Note: The idea behind brain-only plastination is of course identity preservation -- to "save" the true essence of the deceased animal (or person), so that its unique personality may be restored or recreated and inserted into a cloned or virtual body at some future date. From a purely practical perspective, the rest of the body doesn't need to be preserved, though it is highly recommended to have some cell samples stored with one of the cryonics organizations (see below) because plastination might damage the DNA. The latter is needed for cloning and additional identity reconstruction. Alternatively, you could use alcohol preservation (see above) to store the brainless remains, or simply make sure that at least some teeth and large bones -both traditionally used by researchers and forensic detectives to extract DNA long after the rest of the body has decomposed- remain cool and intact. Needless to say, burial is always preferable to cremation.

Whole-body plastination, though technically quite feasible and preferable from an aesthetic perspective, would probably be too expensive to fall in the "low budget" category. Still, people who would like to preserve their entire pet and don't mind paying somewhere between 5-15 thousand (?) EUR for it should definitely contact VisDocta. Again, separate cell sample storage would be highly recommended.

Wessington Cryogenic's Director series mini dewars.

Option #3: Buy or hire a small liquid nitrogen container, the kind that's normally used for the storage of small biological specimens in labs etc. Click here for some examples -- especially the D-4000 model at the bottom of the page looks quite promising.

Advantages: "Mini dewars" can have very favorable boiloff (LN2 evaporation) rates due to their advanced insulation and small necktube diameter, and only need to be refilled a couple of times a year according to the manufacturer(s). This, combined with their relatively mild pricing (D-4000: 1,745 UK Pounds, D-2000C: 1,525 UK pounds, see picture above), light weight, and compact size could make them a fair alternative for DIY pet preservations (or even human neurosuspensions, if you're willing & able to defy/outsmart the deathist bureaucracy). LN2 storage is probably the best means of identity preservation there currently is, even if you do a straight freeze without cryoprotectants (note: alternatives to straight freezing will probably be added at some point. In the meantime, see for example the article "Freeze and dry later" by Douglas Skrecky in Longevity Report 48). At -196*C decay is negligible, and though severe by current standards, it's not unreasonable to assume that future scientists and/or AIs will use their undoubtedly far superior knowledge regarding ice crystal formation and its effects on tissue to extrapolate the original, "functional" state from the damaged state, certainly if additional, external data (as mentioned earlier) is available.

Disadvantages: The containers' relatively small size and neck diameter are both their strong & weak points. While helping to keep things affordable and manageable, they also make it impossible to store a (larger animal's) whole body, or even a large head -- the largest neck diameter is typically 21,6 centimeters. Most pet brains should fit, though, and if necessary they could even be cut up into two or more pieces (this kind of damage is relatively trivial compared to that caused by ice crystals, and should be relatively easy to repair with nanotech etc.). A bigger issue is the fact that LN2 containers need to be refilled at least several times a year, and the LN2 pricing per liter tends to be pretty steep when such small quantities are involved. On the other hand, it won't be more than, say, 500 - 1,000 EUR a year, which should be affordable to most persons, especially if you share the container with some other enlightened pet owners (and placing the container(s) in an insulated, for example wood & styrofoam box could help to further reduce LN2 boiloff, and thus the annual maintenance costs) . Even a relatively small vessel should be able to accommodate several heads or brains.

Also, liquid nitrogen is dangerous stuff! In order to prevent hardcore freezer burn, asphyxiation, and damage to the unit (which, in extreme cases, might even cause explosions) one has to observe some basic safety precautions. Your dewar / LN2 supplier will (should!) provide you with the necessary info.

Another important point to consider is that it may be illegal in some (many?) areas to deliver LN2 and other sealed gases to private homes. Apparently, this is the case in California.

Tip: In some cases you can get both dewar and LN2 from the same supplier (for example HoekLoos in the Netherlands). Check out the dmoz.org cryotechnology directory for an international list of suppliers, or do a "local" search on Google.

Harris Cryostar cryogenic freezers.

Option #4: Buy or hire a cryogenic freezer, such as the Harris Cryostar. Some of these can cool down to -150*C. (note: alternatives to straight freezing, which is the current DIY standard, will probably be added at some point. In the meantime, see for example the article "Freeze and dry later" by Douglas Skrecky in Longevity Report 48).

Advantages: Cryogenic freezers are high-tech, usually high-quality machines with many user-friendly features. They use electricity instead of liquid nitrogen which eliminates all kinds of (potential) handling & supply problems. They're very "discreet"-looking (i.e. they look pretty much like a regular freezer) as well, and the units are both larger and better accessible than the above-mentioned mini dewars.

Disadvantages: These things don't come cheap; a Cryostar will set you back approx. $16,000 + shipping. Similar pricing can be expected for other brands, give or take a couple of thousand $$/EUR. Because this option is in fact more expensive than having the pet shipped to the USA and stored "professionally" by CI or Alcor, it is only interesting if you plan to purchase a unit with a group of people. Let's say one could, if necessary, fit some 20 - 30 animal (or human!) brains or heads into the freezer (or whole bodies if the animals are small enough), and the total set-up costs are approx. $18,000. If purchased collectively, the costs per person would be $600 - $900 p.p., assuming a group of no less than 20, and no more than 30 people. Annual electricity costs, probably somewhere between $1,000 and $2,000, could be split on a similar basis, making them relatively trivial (somewhere between $30 and $100 p.p.). Even if more than half of the original participants would eventually lose interest and stop paying (payments should ideally be automated and semi-annual or quarterly), the operating costs would remain fairly manageable. Of course, one could also request larger, one-time up front payments, and put (most of) the money in an investment fund like the cryonics organizations do. This approach has its own risks, drawbacks, and advantages, but it's definitely an option. The freezer could be stored at a member's residence, thus eliminating the need to rent space (not that the costs of renting a couple of square meters in some business park would be a huge obstacle in the first place, but it might be safer to store the freezer in someone's home).

Secondary concerns are power & mechanical failures. Packing the specimens in dry ice should add a fairly decent extra safety margin, but moving them to another location in an emergency might be a bit tricky (unless, of course, they've been plastinated or freeze dried). Finally, -150*C will inevitably be less effective against biological decay than -196*C (LN2). For relatively short-term storage (a couple of decades at most -- we're definitely not talking centuries here. Click here to find out why) this may hardly matter, though.

Note: needless to say, cryogenic freezers and mini dewars could also be used for human preservation. Most of the above pros & cons would still apply, with two notable exceptions. First the bad news: the "private", non-medical / scientific storage of human remains is at best a grey area in most countries' legal frameworks, at worst outright forbidden. It might be possible to find some legal loopholes, or even have the laws changed, but this could very well be a slow and frustrating process. It might be necessary to store the freezer / dewar in an American cryonics facility until a solution has been found in Europe. This would obviously add all sorts of extra costs and other hassles, which would effectively wipe out most of the advantages of the collective freezer option. Now for the good news: due to the longer average life span of humans, one might use a simple but effective trick to significantly reduce the costs per person: make the collective larger than the freezer's / dewar's capacity! If the latter is, say, 20 brains (freezer), then one could form a group of up to 100 or so people. Should the first freezer / dewar fill up to capacity, which isn't likely to happen anytime soon judging from cryonics organizations' statistics, the group could simply attract a few more members and buy a second freezer / dewar. "Huge" sums are reduced to relatively manageable amounts if you join forces and harness the power of economies of scale. United we freeze, divided we rot! If a location in Europe can be found where frozen human remains can be stored legally, or if interested parties are willing to make this a "clandestine" operation, it might be worth considering.

Option #5: Have the pet freeze dried. [Under construction. In the meantime, check out the freeze drying section --and specifically its commercial pet preservation links-- above if you haven't already. If you live in North America, this might in fact be the best low(er) budget pet preservation solution. Incidentally, the cat and dog pictured at the top of the pet section aren't asleep or freshly deceased -- they're freeze dried. Looks pretty good, huh? From an aesthetic / emotional perspective at least, this seems to be the #1 choice. Once the pet has been freeze dried it should preferably be stored in an oxygen and water proof (plastic, stainless steel, or glass if the pet is small) container which is packed with ample quantities of a desiccant such as calcium oxide. The container should then be put in a (regular) freezer. Though the freeze drying companies claim that the animal can be displayed unprotected at room temperature, protected and refrigerated storage is highly recommended if you're serious about long-term preservation.]

Save Your Pets -- They May Save You

The information used to reconstruct you from cryonic suspension may not necessarily all come from your brain. For example, some memories may be "weak" upon reanimation and may need some extra assistance, such as a videotape of you or some personal notes that you had written, to put them firmly back into place. Also, everyone who knows you has a great deal of information about you, much of it unconscious. Thus, having your friends and family cryonically suspended may also improve the quality of your reanimation, because extracting their information about you may provide clues to help improve the fidelity of your reconstruction. And if the information about you embodied in your friends and family can help, then why not your pets, too?
-- Kevin Q. Brown, CryoNet archives. The original message can be found here.

For those who see cloning as an acceptable alternative to body / brain suspension: CI also offers pet (and human!) cell preservation services, for members, at no maintenance cost whatever, for only a $49 sampling kit and $49 shipping and cryopreservation fee (total costs: $98). ACS offers a comparable service: preservation of a DNA sample through an arrangement with Third Millennium Research, Inc. of Seattle, Washington. Pricing: $49.50/$50.00 for full members. This preservation is at room temperature in a glass vial. Custody of the vial may be undertaken either by ACS or by the member. Also available for $150.00 is the indefinite cryogenic storage of a biological tissue sample. This does not include the costs of taking the sample, shipping costs, etc. It is not quite clear, however, whether either of these (ACS's) options is available to non-members as well, or indeed available at all (contact them for more info). Alcor was setting up a separate, for-profit company called Cells4Life, Inc., that would specialize in tissue sample storage (for the general public as well as Alcor members), but the initiative has apparently been cancelled / postponed indefinitely. There are several other companies that offer cell storage services, but these tend to be considerably more expensive than CI & ACS'. See the list below for some (old, so pricing & other details may have changed) examples.

• Canine Cryobank Has a new, easy sampling protocol that only requires a blood sample. Kits are $150.00 each to a pet owner, costs for the cell cultures are US$365.00, and storage is $75.00 per year (there might also be a separate "processing fee" of $215.00 -- this is not entirely clear). Contrary to what the name suggests, the do accept other mammals (and their semen, by the way), not just dogs. Worldwide service. Claim to have been around, as sperm freezers, for at least 17 years, which is a great plus (but again, by no means a guarantee for anything).
  
  
• Genetic Savings & Clone (GSC) Brought to you by the people behind the world-famous Missyplicity dog-cloning project. The price for "standard" service orders is $895 each, plus shipping. There's also an emergency service for terminal or recently deceased animals (up to one week post-mortem depending on storage conditions), which costs $1395, plus shipping. The annual maintenance fee for Standard jobs is $100.00 per year, versus $150.00 for Emergency jobs (which involve twice as much tissue). The first year's maintenance is included in the initial service fee for both grades. Skin samples (biopsy) required. All in all this looks like a very professional, albeit somewhat expensive, service.
  
  

The Human Cloning Foundation has the largest, busiest, most interactive pro-cloning site on the internet. Here you can join their fight against popular & bureaucratic ignorance, hysteria and prejudice!

Cryogenic tissue storage could be used in combination with plastination or some other relatively cheap & convenient form of chemical preservation, for example, to preserve as much structure and genetic information as possible. We'll stay on the lookout for other (possibly better) alternatives, though. Join the mailing list if you want to be kept up to date regarding these and other developments.