Think about "hyperquenching" (a high-falluting name meaning to use a stream of gas to blow off the cold layer that accumulates above the surface of the liquid nitrogen). We just blow some nitrogen at the surface of the dewar, very low tech...but it works. Importantly, you can use a more leisurely pace when plunging, so that you place the loop straight into the vial without fear of catastrophe.
Warkentin M, Berejnov V, Husseini NS, Thorne RE (2006) Hyperquenching for protein cryocrystallography. Journal of Applied Crystallography 39: 805-811
Warkentin M, Thorne RE (2007) A general method for hyperquenching protein crystals. Journal of Structural and Functional Genomics 8: 141-144
On 24 Apr 2012, at 10:20 AM, David Gallagher wrote:
> Hi all,
>
> I've been using a Belle technologies anaerobic glovebox with in built microscope and liquid nitrogen dewar port in an attempt to harvest and cryo-cool crystals in an oxygen free environment.
>
> I've been having some problems with icing and think this is most likely due to slow speed that it is possible to plunge loops into the liquid nitrogen. I've been plunging loops straight into vials preloaded into an ESRF puck (with pusher). This requires more care than what I would ordinarily do (i.e. plunging into bulk liquid nitrogen then and manouvering into a vial afterwards and then clipping said vial into a cane) and so takes longer - perhaps leading to icing. The latter technique is not available as the glovebox set up means that the dewar can only be reached by my right hand - the microscope is in the way!
>
> Does anyone have any experience of a similar set up and if so have some advice as to how I can overcome this problem?
>
> Many thanks,
>
> Dave Gallagher
>
>
> --
> David Gallagher
> PhD Student
>
> MRC Mitochondrial Biology Unit
> Wellcome Trust / MRC Building
> Hills Road
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> CB2 0XY
>
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