• Beryl@jlai.lu
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    3 days ago

    You’d actually want to freeze them as fast as possible, to prevent the growth of large ice crystals that would tear the cell apart. That’s why you do it by dunking them in liquid nitrogen. But yeah frozen bacteria are basically immortal.

    • phdepressed@sh.itjust.works
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      3 days ago

      No you add DMSO (5-10%) and freeze slowly. Using a Mr frosty or similar. Otherwise a few hours at -20, then -80, before the LN2.

      Just chucking in LN2 is going to have terrible recovery. That might have been done with HeLa way back when but certainly isn’t standard anymore.

      • Beryl@jlai.lu
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        3 days ago

        I mean obviously you’d use DMSO or glycerol, I just didn’t want to get too technical. That being said I’ve always snap-frozen bacteria with LN2 and it worked just fine. Now for eucaryotic cells, sure, you’d want to go slow.

        Edit : ok now re-reading the meme I understand why you thought I was talking about eucaryotic cells. My bad !

    • Contramuffin@lemmy.world
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      3 days ago

      You freeze mammalian cells by dunking them in LN2? I’ve… never heard of anyone do that. I’ve always put them in either a Mr. Frosty or a styrofoam conical holder (makeshift Mr. Frosty)

      • Beryl@jlai.lu
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        3 days ago

        I guess I forgot about the first part of the meme and was talking bacteria, sorry. For eucaryotic cells sure you’d take your time in a -80°C first.

  • Allero@lemmy.today
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    2 days ago

    As someone who just borked a bacterial culture that is merely three months old, I can tell not all bacteria are made equal :D

  • tetris11@feddit.uk
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    3 days ago

    whilst I approve of the use of Limmeh, I’m gonna need more context on the bacteria