[3dem] contamination in cryo samples

[Eric Gilles Hanssen]

Hi Nadav,
We had exactly the same thing happening in our lab. The humidity in the room was way to high after some renovations we undertook. We dropped the room humidity to ~30% which made things much better, we still had some slight issues but after changing the zeolite (that was believe or not 10 years old) in our 626 for the new carbon pack the issue completely disappeared.
Regards
Eric

----------------------------------------------------------------------------
A/Prof Eric Hanssen

Head - Advanced Microscopy Facility
Adjunct Associate Professor - Department of Biochemistry and Molecular Biology

Bio21 Molecular Science and Biotechnology Institute
30 Flemington Road - The University of Melbourne - Victoria 3010 - Australia
email: ehanssen at unimelb.edu.au<mailto:ehanssen at unimelb.edu.au> | Office: +61 3 83442449 | Microscope: +61 3 83442509 | Fax: +61 3 9347 826


On 1 Sep 2016, at 02:01, Nadav Elad <nadav.elad at weizmann.ac.il<mailto:nadav.elad at weizmann.ac.il>> wrote:

Dear all

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.

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.

Thank you for your help

Nadav

--
Nadav Elad, Ph.D.
Electron Microscopy Unit
Weizmann Institute of Science
Rehovot, Israel
Tel: +972 (0) 8 934 2115
Mobile:  +972 (0) 52 3909 420
Email:  nadav.elad at weizmann.ac.il<mailto:nadav.elad at weizmann.ac.il>

<contamination.jpg>
_______________________________________________
3dem mailing list
3dem at ncmir.ucsd.edu<mailto:3dem at ncmir.ucsd.edu>
https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ncmir.ucsd.edu/pipermail/3dem/attachments/20160901/4f3390c7/attachment.html>