Freezing medium - (May/29/2008 )

Hi, What is the most commonly used freezing medium for cell lines?
I used 90%serum + 10% DMSO. Is the percentage of DMSO acceptable? Any other suggestion?
Can I use 95% serum + 5% DMSO as freezing medium?

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For any ordinary cell mammalian cell line I use 20% serum and 10% DMSO. Meaning if you want to make it from DMEM medium, you will take 7 ml DMEM, 2 ml FCS and 1 ml DMSO.

If I already have 10% DMEM with antibiotics, I would take 8 ml of 10% DMEM, 1 ml serum, 1 ml DMSO.

More: http://search.vadlo.com/b/q?sn=158621799&a...lines&rel=0

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What is the purpose of adding 10% DMSO to the freezing medium?

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depends on cell line; try to find information at, f.i., www.atcc.org

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If I can be relied upon any "deep basic information", I believe that it prevents ice crystal formation within the cytoplasm. There. Perhaps I propagated my own fancy.

For an ideal freezing condition for your particular cells, you should try to search/call ATCC as bearer pointed out. Freezing and Thawing works in a broad range of media, serum conc, but one size doesn't fit all perfectly, and may result in less efficient recovery.

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Adding either 5 or 10% DMSO to the freezing medium (amount depends on the cell line, check the documentation that came with the line or contact the source of the line for the optimal amount) acts as an antifreeze, retarding the development of ice crystals as the medium cools. As these crystals are what does much of the killing when cells are frozen and thawed, keeping them to a minimum is a good thing.

HOWEVER, DMSO is poisonous to cells at room temperature. As such, you'll want to start cooling as soon as your cells are in the solution, and you'll need to dilute and/or entirely replace the freezing medium with standard medium once you thaw the cells. Again, whether you dilute or replace depends on the cell line.

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