# Long term storage of ARS and Calc Gluc



## defaced (May 23, 2005)

What scheme is used to store these long term? Is it possible to store them once they're opened?


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## rozdaboff (Feb 27, 2005)

Keep ARS out of the light. Since it is basically just a salt solution, there isn't much risk of bacterial contamination. Ed has mentioned that he has seen algal growth in it though - so keeping it out of the light would prevent that.

Cal-Gluc is a little more difficult to store. It's a sugar solution - so it can be easily contaminated by bacteria and mold. Once you open a bottle - it is very prone to contamination, so store it in the fridge. When you go to use an older bottle - check it for cloudiness, presence of mold.

I was just wondering today about diluting a bottle down - and then freezing aliquots to thaw as needed for use. I don't know what (if anything) that would do to the important ingredients (Chemist I am not) - but it could be worth a try.


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## defaced (May 23, 2005)

Thanks Oz. 

I had thought about portioning out a bottle of Calc Gluc into 1 or 2oz cups and freezing them but on the bottle it says to store it between 15 and 30C and keep from freezing.


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## Ed (Sep 19, 2004)

I make up 5 gallons of ARS at a time and if I keep it out of direct light so it doesn't grow algae, I have used it after it has sat for more than a year. Just make sure that the bottle is tightly closed to prevent evaporation. 

I wouldn't suggest diluting out and freezing the calcium gluconate as it would be difficult to prevent contamination which would allow bacterial growth before freezing and upon thawing. 
In addition, the solution wouldn't freeze uniformly (check out freeze distillation for a discussion http://en.wikipedia.org/wiki/Freeze_distillation) which can cause issues if the whole aliquot isn't thawed and mixed before use (and allows for greater bacterial growth during the thawing process..). 

Ed


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## defaced (May 23, 2005)

Thanks for the comments Ed.


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## rozdaboff (Feb 27, 2005)

Ed said:


> I wouldn't suggest diluting out and freezing the calcium gluconate as it would be difficult to prevent contamination which would allow bacterial growth before freezing and upon thawing.
> In addition, the solution wouldn't freeze uniformly (check out freeze distillation for a discussion http://en.wikipedia.org/wiki/Freeze_distillation) which can cause issues if the whole aliquot isn't thawed and mixed before use (and allows for greater bacterial growth during the thawing process..).


I wasn't really concerned as much with contamination Ed, - as sterile dilution and sterile preparation of aliquots is an issue you can get around with the appropriate equipment. Also - I would have access to rapid freezing (-80 C and LN2 if necessary). I was more concerned about what may happen to the solution during the freezing process.

Any thoughts?


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## Ed (Sep 19, 2004)

I think LN2 would be going overboard just a little... 

if you have access to aseptic techniques that would allow you to dilute and freeze then it should be fine. The calcium gluconate/glubionate should be stable with respect to the freezing. 

Ed


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## jejton (Sep 3, 2006)

How do you make ARS? What is a good place to get calcium gluconate?


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## rozdaboff (Feb 27, 2005)

See here:

http://www.dendroboard.com/phpBB2/viewtopic.php?t=22383


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## Ed (Sep 19, 2004)

There is a recipe here http://www.caudata.org/cc/articles/bloatEDK.shtml or you can order it premixed from Fisher Scientific. 

Calcium gluconate can be purchased from some of the board members or from places that care large animal supplies. 

Ed


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## Steve (Apr 8, 2006)

The Calc Gluc i got has a rubber sealed lid, to get it out i use a hyperdermic so i can measure quantities, it basically self seals once the needle is drawn out so any ideas how long that will last?

Just curious

Regards

Steve


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## Ed (Sep 19, 2004)

It depends on how quickly it gets contaminated (like using a contaminated needle or the gasket fails). 

Ed


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