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<div class="moz-cite-prefix">Nadav,<br>
<br>
We have recently had similar contamination problems.<br>
<br>
Although it sounds as if you've already tried alternative holders,
hor us, we (after a lot of troubleshooting!) found that switching
from our Gatan 914 holder to a Gatan 626 holder solved the
problem. We don't yet have a rationale for why this worked, yet,
unfortunately. Gatan suggest that the spring clamp on the 914 may
need replacing and we hope to do this ASAP.<br>
<br>
best,<br>
<br>
Morgan<br>
<br>
<br>
<br>
On 01/09/2016 10:00, Nadav Elad wrote:<br>
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<p class="MsoNormal">Dear all<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We are having a serious contamination
problem in our cryo preparations and would be grateful for any
suggestion. Although this issue has been discussed in the past
in this forum, the solutions raised do not seem to work. The
attached image shows the contamination on a bad day. I am
referring mainly to the lighter, smaller particles (10-20 nm)
which are the most persistent. They seem to be above or below
the ice layer and are the first to evaporate under the
electron beam. The concentration of contaminants is variable.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We are using a Leica EM GP plunger for
freezing, and Tecnai T12 and F20 microscopes with Gatan side
entry holders. We have tried to replace the ethane cylinder
and are in the process of ordering a third one, cleaning the
glow discharger machines, different cryo holders, different
cryo-transferring units and grids of varying sources. There
seems to be no leaks in the compustages of the microscopes.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you for your help<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Nadav<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">--<o:p></o:p></p>
<p class="MsoNormal">Nadav Elad, Ph.D<span dir="RTL"></span><span
dir="RTL"></span><span dir="RTL"
style="font-family:"Arial","sans-serif""
lang="HE"><span dir="RTL"></span><span dir="RTL"></span>.<br>
</span>Electron Microscopy Unit<span dir="RTL"
style="font-family:"Arial","sans-serif""
lang="HE"><br>
</span>Weizmann Institute of Science<o:p></o:p></p>
<p class="MsoNormal">Rehovot, Israel<span dir="RTL"
style="font-family:"Arial","sans-serif""
lang="HE"><br>
</span>Tel: +972 (0) 8 934 2115<o:p></o:p></p>
<p class="MsoNormal">Mobile: +972 (0) 52 3909 420<o:p></o:p></p>
<p class="MsoNormal">Email: <a moz-do-not-send="true"
href="mailto:nadav.elad@weizmann.ac.il">nadav.elad@weizmann.ac.il</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<br>
<p><br>
</p>
<div class="moz-signature">-- <br>
<font size="-1">
<b>Morgan Beeby</b> | Lecturer in Structural Biology<br>
Department of Life Sciences<br>
Sir Ernst Chain Building<br>
Imperial College London<br>
South Kensington Campus<br>
London, SW7 2AZ, UK<br>
<br>
<i>t:</i> +44 (0)20 7594 5251<br>
<br>
<a href="http://www3.imperial.ac.uk/people/m.beeby">http://www3.imperial.ac.uk/people/m.beeby</a><br>
<a href="https://twitter.com/beebylab"><b>@BeebyLab</b></a></font>
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