Storage of media supplements

[Marie Wheeler]

Hi Toot and fellow BMOers, 

Thank you so much for this very helpful group! I have read so much from here and gleaned so many insights as I start making comBOs in my lab.

I'm reaching out because companies report different stabilities of powders and their solutions for the media additives of the comBO protocol. I just want to confirm I am storing these correctly such that they will not degrade from batch to batch. 

• Heparin - store solutions at 4C in the dark
• β-glycerophosphate pentahydrate - store solutions at room temp, in the dark
• L-glutamate - store solutions in aliquots @ -20C (avoid freeze-thaw)
• L-Ascorbic acid - solution is very unstable, need to make fresh aliquots each time
• L-Ascorbic-2-phosphate - solution can be stored in aliquots at -80C for 6 months (ideally under nitrogen, but our lab doesn't have the tools for that).
  • Does your lab use ascorbic acid or ascorbic-2-phosphate?

Thank you in advance,

Marie

[Abdullah Khan]

Thanks for the kind words Marie ! 

You are correct on all accounts - we use ascorbic -2 phosphate and either make it fresh from powder when needed, or make a stock and dilute it down. We've not had any problems with these - we use this for cardiac diffs too and those are very temperamental, so I'm reasonably sure this works well! 

Thanks for tooting, 

Abs 

[Zora Baumann]

Hi Abs, 

On the note of L-ascorbic acid; have you ever checked the difference it makes if you use the biologically active L-ascorbic acid versus the 2-phosphate? 

I have been using L-ascorbic acid itself (aliquots stored at -80°C for max. 3-4 months, thaw and discard) and all seems ok; but I wonder if changing it makes a difference.

Cheers,

Zora

[Abdullah Khan]

Hey Zora - never really tested this - but it comes down to how bioavailable the L-ascorbic acid you're using is!

Abs