Cells – Slow Freeze & Fast Thaw

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    • #8176
      Endothelial-cell
      Participant

      I have a question that is during cell culture, why is that we have slowly freeze the cells and we have to be fast during thawing the cells??

      Thanks!

    • #75787
      mith
      Participant

      Might have to do with crystal formation

    • #75828
      konstantin
      Participant
      quote mith:

      Might have to do with crystal formation

      What crystal formation????? 🙂

    • #75830
      canalon
      Participant

      water->ice

    • #75916
      konstantin
      Participant
      quote canalon:

      water->ice

      and water > ice what issue can you suggest?

    • #75917
      mith
      Participant

      Ice- cream!

    • #75966
      Darby
      Participant

      As I understand it, the thaw cycle is tricky because crystals can expand among the thawing cells and rip them up.

    • #76512
      biohazard
      Participant

      During freezing, water forms ice crystals that damage the cell membrane. Hence mammalian and other sensitive cells usually die no matter how you freeze them, unless you put some additives to the freezing medium – such as DMSO. The optimal rate of freezing is around 1 degree of Celsius per minute, if I recall correctly.

      What comes to thawing, the situation is a little bit different. The DMSO – even though it prevents ice crystals – is toxic to cells. Therefore it is wise to thaw the cells quite quickly and then remove the DMSO. One of the main problems during thawing is not the crystal formation, but osmotic shock; too fast dilution of the cryoprservant may damage the cells. In some protocols glycerol is used instead – it is less toxic, but has bigger risk of causing osmotic shock. There are also several other issues involved, which in together make fast thawing better than slow one.

    • #76698
      konstantin
      Participant
      quote biohazard:

      During freezing, water forms ice crystals that damage the cell membrane. Hence mammalian and other sensitive cells usually die no matter how you freeze them, unless you put some additives to the freezing medium – such as DMSO. The optimal rate of freezing is around 1 degree of Celsius per minute, if I recall correctly.

      What comes to thawing, the situation is a little bit different. The DMSO – even though it prevents ice crystals – is toxic to cells. Therefore it is wise to thaw the cells quite quickly and then remove the DMSO. One of the main problems during thawing is not the crystal formation, but osmotic shock; too fast dilution of the cryoprservant may damage the cells. In some protocols glycerol is used instead – it is less toxic, but has bigger risk of causing osmotic shock. There are also several other issues involved, which in together make fast thawing better than slow one.

      good answer…:)

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