[3dem] carbon detaching from grids

[Anna Sartori Rupp]

Hi Cheri,
We recently experienced exactly the same problem with the two latest
purchased boxes of quantifoil gold R2/2 grids. We used the same glow
discharge machine (ELMO) and the same settings that we normally use and we
experienced that when we put the grids in a buffer like PBS or HEPES + 2%
PFA the carbon was detaching on almost all the grids.
To see where the problem could come from we used two very old batches of
quantifoil grids and repeated the same procedure , but in this case the
carbon remained nicely attached to the grids.

So it could be that your problem might not be due to your plasma cleaner
but rather to the new way quantifoil is manifacturing their grids.

 I contacted quantifoil and sent them the corresponding pictures, they told
me that in fact they recently changed their carbon film deposition
parameters (he talked about different plasma cleaner conditions...) and
they told me that they would look into it , but I haven t heard back from
them yet.
It would be great if you could also contact them to report your problem.
I hope this helps,
Ciao
Anna

-------------------------------------------------

Anna Sartori-Rupp , PhD
Ultrastructural Bioimaging Unit
Institut Pasteur,
28 rue du Dr Roux
75015 Paris, France


Il giorno Gio 6 Dic 2018, 9:12 PM HAMPTON, CHERI M CTR USAF AFMC AFRL/RXAS <
cheri.hampton.ctr at us.af.mil> ha scritto:

> Hi all,
>
>
> I have suddenly begun experiencing the carbon detaching from my QF R2/1
> grids when submersed in buffer and when applying proteins for blotting and
> cryo-plunging. I have tried two different lots of grids, and now I am
> suspicious of the facility's plasma cleaner that I have been using to glow
> discharge. All settings and timings have remained constant on my part. I
> plan to seek out another plasma cleaner to do a comparison test, but
> meanwhile, what kinds of solvents or materials placed in the plasma
> cleaner/glow discharge unit might linger and cause problems? I'd like to
> justify having a "clean" one just for TEM :)
>
>
> Thanks for your input,
>
> Cheri
>
>  ~'~'~'~'~'~'~'~'~'~'~
> Cheri M. Hampton, PhD
> Research Microscopist
> UES, Inc.
> AFRL/RXAS
> 2179 12th St, B652/R122
> Wright-Patterson AFB, OH 45433-7750
> (937) 255-9081
> cheri.hampton.ctr at us.af.mil
>
>
>
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