[3dem] glow discharge carbon coated grids several times?

[Haaris Ahsan Safdari]

Hi Tobias,

We routinely use continuous carbon quantifoil grids for our work (generally
3nm layer). I did use once few grids which were stored and were re-glow
discharged next day. Unfortunately, all the carbon layer on the hole was
completely destroyed. I spent lot of time moving across the atlas of the
grid to find even few gridsquares good enough for data collection, but
failed to do so. So in my limited experience, it is better not to store
grids which are somehow not being used after one glow discharge.

Please see one gridsquare image (R3/3 quantifoil) and one hole image. You
can see how the carbon was ripped off and I could see hint of it at the
corner of hole (with dark patches around holes).

Regards
Haaris



On Fri 8. Sep 2023 at 15:09, Tobias Furstenhaupt <furstenh at mpi-cbg.de>
wrote:

> Dear colleagues,
>
> we regulary use holey carbon coated copper grids in our plunge freezer.
> Naturally we glowdischarge them before. We use a Pelco easiglow at 15 mA,
> 0.4 mbar for 30 seconds on each side).
> To be on the safe side, we glow discharge always 1-2 grids more than we
> probably need for plungefreezing. Does anybody of you have any experience
> if leftover grids can be reused? Ie that we put the grids back in the box
> and glow discharge them a second time and use them?
> Formvar coated grids dont survive a second glow discharge (the plastic
> rips broadly open) but what about a carbon coat? Does anybody know?
>
> cheers
> Tobias
>
>
> -----------------------------------
> Tobias Fürstenhaupt, PhD
> head of Electron Microscopy
> Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)
> Pfotenhauerstrasse 108
> 01307 Dresden, Germany
>
> mail: furstenh at mpi-cbg.de
> phone: (+49) (0)351 210-2690
> cell: (+49) (0)176 / 44498706 (NEW!)
> _______________________________________________
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>
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