Posted 08 September 2009 - 12:03 PM
Posted 08 September 2009 - 01:03 PM
I experienced a similiar problem when I first started working with frozen cell cryovials. Unfortunately the only thing I could suggest to you is to very quickly take your vial from storage and transfer it very quick to a biological safety cabinet and then unscrew the cryovial lid off to avoid pressure build up. This ought to stop the cap from exploding off and wasting the vial contents. Let me know if this works.
Posted 08 September 2009 - 04:41 PM
1) Try a different brand of cryovial - we use cryo-s from Nunc (I think). It will help if they have a silicone gasket and are not over-tightened.
2) loosen the cap slightly immediately after removal from the LN2
3) put the tube inside one of the products that are designed to stop this happening (cryoflex from Nunc is the product that springs to mind, there will be others)
Never thaw the samples completely on dry ice, ice (or preferably dry ice) should only be used to transfer the cells from the LN2 to the waterbath where you are thawing the cells. The general rule for cells is freeze slow, thaw fast.
Dry ice is also warm enough (-86˚C) that the LN2 (-196˚C) will evaporate almost instantly.