Glyoxal fixative
Posted: Mon Sep 09, 2019 9:03 am
This post was made by cryomorph at the end of a different thread, but I think it deserves its own thread.
Hi Jordan....
Here is a copy of a post that I put up on NCN earlier today. Save me having to write it all out again. Thought I'd copy it over to this thread as I know you don't 'tune in' to NCN so much these days. Maybe it's something you have already looked into, but either way, I would be interested to hear your views on this one.
Roman.....
Although the recent ASC research for cryonics purposes was based upon the use of formaldehyde/glutaraldehyde fixation, which is generally accepted as one of the most efficient permanent fixers available. There is at least one alternative to the more commonly used fixers that could provide some of the benefits without the permanence of the 2nd phase cross linking of molecules that formaldehyde and glutaraldehyde routinely produce.
Conventional fixing is a 2 phase process, the first phase of cross linking which is reversible takes about 24 - 48 hours to complete however, the 2nd phase (irreversible), can take up to 30 days dependent upon certain conditions mainly due to the process being temperature sensitive and given that cool down commences immediately after perfusion, it is likely to take substantially longer in most cryonics cases.
By comparison oxaldehyde based fixers such as Glyoxal penetrate tissue faster and assuming the preparation conditions are met, provide 1st phase fixation (reversible), only. It does not continue to go on to produce the 2nd phase of permanent cross linking of molecules. Oxaldehyde fixing is far less aggressive than conventional fixers and produces substantially less undesirable product than both formaldehyde and glutaraldehyde. It is also much less toxic to clinicians and lab workers than glutaraldehyde and formaldehyde, needing no special venting equipment. (Once diluted into water it is held in solution and doesn't vapourise).
So far I've been unable to find any papers regarding the efficacy of Glyoxal for whole organ preservation, everything I've found so far relates to histological research which isn't ideal it has to be said. Having said that it would appear that it has potential for use within cryonics, but some experimentation would be necessary in order to completely understand its mechanisms and effects prior to using it as part of any suspension procedure.
Tim
Hi Jordan....
Here is a copy of a post that I put up on NCN earlier today. Save me having to write it all out again. Thought I'd copy it over to this thread as I know you don't 'tune in' to NCN so much these days. Maybe it's something you have already looked into, but either way, I would be interested to hear your views on this one.
Roman.....
Although the recent ASC research for cryonics purposes was based upon the use of formaldehyde/glutaraldehyde fixation, which is generally accepted as one of the most efficient permanent fixers available. There is at least one alternative to the more commonly used fixers that could provide some of the benefits without the permanence of the 2nd phase cross linking of molecules that formaldehyde and glutaraldehyde routinely produce.
Conventional fixing is a 2 phase process, the first phase of cross linking which is reversible takes about 24 - 48 hours to complete however, the 2nd phase (irreversible), can take up to 30 days dependent upon certain conditions mainly due to the process being temperature sensitive and given that cool down commences immediately after perfusion, it is likely to take substantially longer in most cryonics cases.
By comparison oxaldehyde based fixers such as Glyoxal penetrate tissue faster and assuming the preparation conditions are met, provide 1st phase fixation (reversible), only. It does not continue to go on to produce the 2nd phase of permanent cross linking of molecules. Oxaldehyde fixing is far less aggressive than conventional fixers and produces substantially less undesirable product than both formaldehyde and glutaraldehyde. It is also much less toxic to clinicians and lab workers than glutaraldehyde and formaldehyde, needing no special venting equipment. (Once diluted into water it is held in solution and doesn't vapourise).
So far I've been unable to find any papers regarding the efficacy of Glyoxal for whole organ preservation, everything I've found so far relates to histological research which isn't ideal it has to be said. Having said that it would appear that it has potential for use within cryonics, but some experimentation would be necessary in order to completely understand its mechanisms and effects prior to using it as part of any suspension procedure.
Tim