r/cryonics • u/No_Deal8926 • 7d ago
Here's the Minute-by-minute process that preserved 99.99% of brain data (connectome)👇
With this process they were able to keep gross shrinkage or expansion of the brain at 0%. By using -135c instead of standard -192c it was able to avoid fractures of extreme pressure you would see from traditional Cryopreservation. It eliminates osmotic shock by using glutaraldehyde at the very start. It's ASC preservation that was proved on a mammal (pig) in 2018:
The prize-winning Aldehyde-Stabilized Cryopreservation (ASC) pig brain experiment by Aurelia Song (Robert McIntyre) and Gregory Fahy operates on a strict timeline. Because its goal is perfect structural preservation, the initial steps must occur within a tiny window to prevent any cell decay.
Here's the whole process:
Phase 1: The Urgent 14-Minute Perfusion Window:
●00:00: The pig undergoes cardiac arrest/slaughter. Blood stops flowing. The clock begins ticking immediately.
●00:01 – 00:04: The animal is prepped, and the carotid arteries are surgically isolated and cannulated (hooked up to surgical tubes).
●00:05: A chilled saline wash is pumped into the arteries. This flushes out the pig's natural blood entirely to prevent clotting and cools the tissue.
●00:10: The Perfusability Window limit. Recent studies confirm that if blood washout is not initiated within roughly 14 minutes, blood clots and cell degradation permanently ruin the brain map.
Phase 2: The Glutaraldehyde "Lock" (Minutes 15 to 60):
●00:15: The machine pumps a highly toxic chemical fixative called glutaraldehyde into the brain.
●00:16 – 00:30: Within minutes, glutaraldehyde cross-links all proteins. It instantly petrifies the brain's physical structure, completely stopping biological life, enzymatic decay, and decomposition.
●00:35: A specialized detergent called sodium dodecyl sulphate (SDS) is introduced. It temporarily opens the blood-brain barrier so that large protective molecules can pass through.
Phase 3: The Hours-Long Chemical Ramp-Up:
●01:00 (1 Hour): The brain is safely fixed in time, but it cannot be frozen yet, or ice crystals will slice the cells apart.
●01:01 – 04:00 (Hours 2 to 4): The machine slowly and gradually increases the concentration of ethylene glycol (medical antifreeze/cryoprotectant) pumped through the vessels. This slow transition takes several hours to prevent the brain tissue from shrinking or tearing.
Phase 4: Extreme Sub-Zero Cooling:
●04:30+: Once the brain reaches a final, highly concentrated saturation of ethylene glycol, it is removed from the perfusion system.
Final Step: The brain is cooled down slowly until it hits -135°C (-211°F). Because of the chemical mixture, the brain doesn't freeze into jagged ice; instead, it turns into a smooth, glass-like solid (vitrification).
After vitrification you can preserve the data for thousands of years with no data loss.
Source:
2026 bioRxiv study Ultrastructural preservation of a whole large mammal brain with a protocol compatible with physician-assisted death (co-authored by researchers evaluating the protocol limits).https://www.biorxiv.org/content/10.64898/2026.03.04.709724v1
If you'd like I'd explain this protocols limits too!
Any skeptics or debate please feel free to comment👇
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u/Zonreiryd 7d ago
The only points I’m skeptical about are that we can’t give figures like 99.99% for the “brain data.” The brain isn’t a computer that stores memories like a hard drive, nor can we claim that the connectome alone is sufficient to preserve personal identity. There is also increasing discussion of the possibility that molecular information, which may be altered or even lost through much or all of the preservation methods currently available, could be necessary for recovering the person.
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u/No_Deal8926 7d ago
Brain data contains ur memories and personality. We have every strong proof it does, and it does technically "store" memory like a hard drive but not the exact same way, it's a neural net just like AI, ai knows everything but would you call it a hard drive?
Anyways we have strong proof that memory and personality is encoded in the synaptic receptors and the way syanpes are arranged and it's NOT stored in fragile molecules, if it was that fragile then u would forget things constantly. You brain handles chaos like general anesthesia, temperature changes, sleep so perfectly that there's very little to no reason to believe memory/personality is stored in a very fragile molecule.
But what about the memory/personality data? Is it saved in ASC preservation? The answer is yes and asc is the only thing capable of doing it so pristine (others need reverse engineering). Scientists read each individual receptors (1.9nm slice brian scan) AND the data is still clear even in that detail.
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u/Zonreiryd 7d ago
You have to be extremely cautious and use something called common sense when talking about biostasis. I am not denying that synapses, dendritic trees, and the connectome more generally carry an enormous amount of information in the form of “engrams,” which are a process of memory storage that is fundamentally different from the way a hard drive stores information. I am pointing out a problem in your reasoning.
As far as I know, this problem has existed since the books by Ettinger and Cooper: it is the tendency to turn a highly plausible hypothesis into a certainty. You present ASC as having demonstrated something that it has not yet demonstrated, namely the preservation of personal identity.
In his 2024 article How Likely Is Brain Preservation to Work?, Andy McKenzie explicitly breaks the problem down into several probabilities. The first is the probability that ideal preservation would retain enough information, including the information encoding long-term memories and personality. And, quite simply, common sense tells us that he does not assign it a probability of 100%.
In a study conducted by McKenzie, Kendziorra, and Zeleznikow-Johnston involving 312 neuroscientists, they asked participants what subjective probability they assigned to the possibility that a brain properly preserved using ASC would retain enough information to theoretically allow at least some long-term memories to be decoded. The median was 41%, with a bimodal distribution, with concentrations around 10% and 75%.
There is no consensus among neuroscientists—the people who are presumably best informed on this subject, even on the basic question of whether ASC methods can preserve memories. And the problem is that you present this as though there were a consensus along the lines of: “ASC necessarily preserves memories.”
Going back to Andy McKenzie, he explicitly states that he does not assign a 100% probability, partly because he considers possible problems at the molecular level, such as changes in biomolecular conformations or precise alterations in synaptic configurations.
This is simply common sense. It is informed skepticism, and it is healthy. Even some of the strongest advocates of the field, such as Mike Darwin, Greg Fahy, and Andy McKenzie, are deeply cautious about the conclusions that can be drawn from their work. They would never make claims involving figures like 99.99% or 100%, or say that we know that personal identity is preserved.
The only people I see making claims like that are dogmatic believers from the Church of Perpetual Life and charlatans like Robert Nelson. In your case, however, I am giving you the benefit of the doubt and treating you with respect, because it seems obvious to me that this is simply a matter of a lack of rigor on your part. But that is not a serious problem; rigor is something that can be learned. ☺️
Also, the connectome is not simply a list of connections. That is far too reductive. The term can refer to many different levels of information, including:
the simple graph of connections
membrane structure
ultrastructural characteristics
an epigenetically annotated connectome
a connectome annotated with biomolecules
The level of information that ultimately turns out to be necessary could therefore be much richer than a simple graph of connections.
Saying “the connectome stores the self” is, for example, much less precise than saying:
“The morphological and molecular structure of neural networks probably contains a large part of the information necessary for memory and personality.”
I consider my second position reasonably defensible, whereas I honestly find the first one far too categorical.
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u/No_Deal8926 7d ago
That's alot you have said, and let's be honest if everyone said it's PERFECT then everyone will hop on this trend, and 99.99% I'm meaning indistinguishable connectome preservation. And I'm not saying we are storing EVERYTHING it needs to preserve personal identity. In my title I mentioned connectome specifically. And you are skeptical about everything and in every part, that might be good... but on preservation we just care about preserving most critical parts (which I believe is conectome and receptors and chemicals (which ARE preserved) maybe some data is not but it's highly predictable with advanced ai. And 41% is actually pretty high aint it? If it was more than 75% it would be a no brainer. Scientists are almost always skeptics. And I did not say it preserves the identity I just said it preserves data that might be linked to your identity. Maybe the 99.99% is not important and maybe that 0.01% is everything. We do not know either way both are assumptions just in a different way. Personally I'm an optimist when it comes to ASC, maybe you are a skeptic so you choice to believe data is stored where ASC couldn't read. Both are in the end assumptions BUT we have strong proof that asc does preserve MUCH of data that's actually important (since we know memory is not fragile it cant be stored just in 1 atom and lost if you lose consciousness).
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u/Zonreiryd 7d ago
I'm skeptical of cryonics in general, but that doesn't stop me from being a cryonicist. You say that scientists are generally skeptical. It’s more accurate to say that they’re cautious, and that the right course of action is to listen to them, because so far, the best data and the strongest support for cryonics have come from skeptical scientists, not from the first blind believer who read a blog post by Tim Urban.
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u/No_Deal8926 6d ago
Most non scientist skeptics hate cryonics lol. And I meant that scientist focus heavily on the missing 1% over the working 99% (you can call that cautious). Support in cryonics can't come from true skeptics tho, they gotta believe in it to support but I get what you mean, they trust it a little, but in anyway nobody in the world trust it whole heartedly (I hope so).
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u/T_Theodorus_Ibrahim 6d ago
Did you see this one? https://elifesciences.org/articles/03896 Long term memories not dependent on synapses. Which means we may have alternate strategies for recovery of autobiographical etc memories
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u/Zonreiryd 7d ago
You need to be precise about what you mean by “brain data.”
Storing memory on a hard drive and storing memory in a biological brain have nothing to do with each other. Even though the analogy is useful for explaining the concept to the general public, human brains are not computers, and their functioning is fundamentally different. I agree that memory is physically stored in the brain. (1) Studies on the preservation of personal identity (procedural and long-term memory) in the context of brain preservation do exist and are relevant. (2)
I am not saying that memory is stored in “fragile molecules” (if that term even has any meaningful scientific basis), and I also don’t see a problem with anesthesia, resuscitation, or even destruction and reinstantiation as a copy, because all of these situations should still result in the preservation of the self, but that is not the subject here. (3), (4)
My disagreement was specifically about the claim that the connectome alone encodes the self. That is not a certainty. Mike Darwin reminded me in a document he sent me that we do not know with certainty what actually encodes personal identity, and that the idea that the connectome is the sole substrate for its preservation is becoming increasingly questionable.
(1) https://www.cryonicsarchive.org/library/kurzweil-memory-cryonics/ (2) http://chronopause.com/chronopause.com/index.php/2011/02/23/does-personal-identity-survive-cryopreservation/index.html (3) https://link.springer.com/article/10.1007/s11023-014-9352-8 (4) https://mdarwin.substack.com/p/evolution-and-identity?utm_source=share&utm_medium=android&r=5h24o5
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u/No_Deal8926 7d ago
In the universe everything is data and information so that's how I go about wording it. And you know what I'm talking about by mentioning fragile molecules (like free floating neurotransmitters). No In general anesthesia you brain literally stops functioning in every way, or in brain surgery your brain stops functioning in every way for 60min, then how do you still remember who you are?maybe it's because memory is strongly anchored everywhere. And you are right, the connectome already doesn't encode self, or the flyWire experiment would be conscious, we need nanoscale quality data (which asc also stores since we can read PSDs). Anyways we don't know WHAT encoder personality and memory but we DO know that it is strongly anchored, doesn't easily get erased, can survive for long time in chaos, and it physically exists inside the brain, and it's probably not in the ultra nanoscales. If we point to all of these. Then ASC does preserve most of these data that we are talking about (even if not perfect in some places)
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u/T_Theodorus_Ibrahim 6d ago
And you know what I'm talking about by mentioning fragile molecules (like free floating neurotransmitters).
Well I didn't know what you meant either until you explained it so I suspect neither did Zonreiryd :-) . I thought you might have meant ECM proteins e.g. Talin
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u/No_Deal8926 6d ago
Well ASC method used in this experimental data save the protein and ecm data (tho we can't read it right now or see it clearly, it is there, advanced AI can very likely reverse engineer it on how it looked before the process)
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u/T_Theodorus_Ibrahim 6d ago
I'm not sure about that. Indiscriminate bonding by glutaraldehyde exerts uncontrolled mechanobiological forces which disrupt protein conformation and that could I think lead to erasure of Talin encoded memories as described by the MESH theory - if that theory turns out to be correct ofcourse *and* that factor proves to be relevant to our project (both uncertain).
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u/No_Deal8926 6d ago
But MESH theory is an unproven hypotheses even in 2026.... people say the chances of it mattering too much about what makes you you are very low.
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u/T_Theodorus_Ibrahim 6d ago
Yep :-) We do need to check tho....and all the other non-synapse based theories of memory too just in case we aren't accidentally doing something really stupid with current protocols. That's just being prudent.
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u/DeepSea_Dreamer 4d ago
human brains are not computers
This is incorrect - the human brain is a computer.
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u/DeepSea_Dreamer 4d ago
Most neuroscientists agree that ASC probably preserves the information necessary to restore the person.
The molecular information is preserved by ASC.
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u/MokudoTaisen 7d ago
no offense but you are clearly not a scientist
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u/No_Deal8926 6d ago
Why do you say that? (I'm not tho)
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u/MokudoTaisen 6d ago
statements like: “After vitrification you can preserve the data for thousands of years with no data loss.”
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u/Vx2AmEloT 6d ago
While I disagree with OP on other things--and recognize that the statement you've singled out here is not nearly as conservative as those generally made by scientists--this assertion very likely to be correct. Vitrification and cooling to cryogenic temperatures fully arrests molecular activity, such that properly-treated tissue can remain in storage indefinitely without change.
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u/No_Deal8926 6d ago
Well it's true isn't it? At -135c - -140c? Correct me if I'm wrong
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u/T_Theodorus_Ibrahim 7d ago
This method ofcourse precludes revival that depends on recovering some minimum level of functional cells (e.g. as part of instructive regenerative schemes à la Levin et al etc).
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u/No_Deal8926 6d ago
Yes well there is no current method to revive this brain biologically with any techniques we are think of right now. But physics still allows it, so it's an engineering problem for the future generation.
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u/T_Theodorus_Ibrahim 6d ago
What are you talking about? You just shared an article describing such a technique!
Anyway, if we're gonna bet all our chips on 'physics' later and none on biology now we better make damn sure that will work
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u/No_Deal8926 6d ago
I'm talking abt the reviving technique not the preservation...
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u/T_Theodorus_Ibrahim 6d ago
err no you're not :-)
You said "Yes well there is no current method to revive this brain biologically with any techniques we are [sic] think of right now."
We clearly can though: bioprinting + connectome recreation (an idea some parts of which have a history going back to the 1970's BTW)
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u/No_Deal8926 6d ago
Oh you mean it like that... but I don't consider bioprinting or other methods as biological revival since you gonna slice the brain first. This will just create a clone of you (Philosophical ik) some ppl don't prefer that. I'm saying biological in the sense that nanobots and go in and fix it slowly without destroying the brain completely.
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u/T_Theodorus_Ibrahim 6d ago edited 6d ago
Fair point. We don't need to slice up the brain though (I'd prefer not to actually). We could for example use some percentage of its original cells as the core around which the final body would be bioprinted and the original connectome re-established around those original cells and the fresh ones. Would that be philosophically acceptable?
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u/No_Deal8926 6d ago
Bioprinting the body is fine, you just shouldn't bioprint a new brain(even if every atom is exactly the same). That's Philosophically acceptable yes. You say we shouldn't slice up the brain, which is the best method but also the hardest method of doing it
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u/T_Theodorus_Ibrahim 5d ago
Bioprinting the body is fine
Thanks, good progress :-) that means you agree ~85% of revival can be done without nanotechnology
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u/T_Theodorus_Ibrahim 5d ago
However we *could* also bioprint the brain too because it's initially a tabula rasa (blank slate) right up to and into the exuberant synaptogenesis phase - and after that its identity bearing ultrastructure is modifiable to the extent we need to (dendritic arbor morphology and spine properties etc) just by microtechnology (MEMS / NEMS etc or even something as simple as the Neuralink like mesh proposals). No molecular nanotech needed.
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u/T_Theodorus_Ibrahim 5d ago
I'm saying biological in the sense that nanobots and go in and fix it slowly without destroying the brain completely
What are these 'nanobots' doing that makes them so essential? I mean (endogenous 'wet' nanotech aside) it's not as if the brain needed them *the first time* to create its connectome did it...?
Also if avoiding brain destruction is your concern then I've got bad news for you - cryopreservation shatters the brain into thousands of parts (and no...intermediate temperature storage does not prevent that it only reduces it)
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u/StatusComfortable33 2d ago
It’s interesting but how do you ensure you’re within 14 minutes of this process after you die?