[3dem] cryo TEM holder for autogrids and ThermoFisher/FEI

Thu Jun 10 02:42:34 PDT 2021

Hi.

We had similar vacuum crashes on a Tecnai with the 626 holder. The problem was solved by replacing the o-rings. (I try to recall the source but don't have it yet.) It might be that the ELSA is a bit heavier and so more sensitive, but it's also possible that the original o-rings were not good. It's generally useful to check the o-ring under a dissecting microscope before cooling down. Sometimes you find strands of lint.

It's also possible to use autogrids in the 626 by inverting the clip ring like a top hat and pressing down. It centers perfectly and holds tight, but the edges of the grid are shadowed. Also it's not easy to get the grid back out if you imagine to reuse it. Keeping the dewar full overnight needs a separate solution, of course.

regards,

Michael

________________________________
From: 3dem <3dem-bounces at ncmir.ucsd.edu> on behalf of Artemis Kosta <akosta at imm.cnrs.fr>
Sent: Thursday, June 10, 2021 12:23:26 PM
To: Dokland, Terje; Tobias Furstenhaupt
Cc: 3dem at ncmir.ucsd.edu
Subject: Re: [3dem] cryo TEM holder for autogrids and ThermoFisher/FEI

Hello everybody

I have extensively tested the Elsa ultra-low profile as I am planning to
buy it soon, here is my experience:

The Elsa takes longer than the 626 to cool down, so my routine is to
cool down the microscope, insert the Elsa, fill its dewar with LN2 and
go away. 30 min later Elsa is at the right temperature and contamination
free in the column....

I had vacuum problems everytime I inserted the Elsa in the column, but
after changing the O-ring, I had no more problems. It seems to me that
the O-ring area is in contact with LN2 and hence damaged fast, so I keep
the loading station a bit tilted towards the tip, to avoid LN2 from
damaging the O-ring...I change the O-ring from time to time, it costs
nothing..and lubricate it with the appropriate vacuum grease (here TF
uses Fomblin). By the way, for my Tecnai, the O-rings are the same for
the Elsa and the 626, I don't know if for other microscopes there are
different configurations..

For screening grids, the 626 is faster and more convenient, for long
collections, the Elsa is better. We don't see the drift problem, but
other users say that each holder performs differently...
Also, the ultralow profile tip is very convenient, but only for
experienced users so that they don't forget to lower the small blades
before inserting or removing the holder..It can be damaged seriously if
someone forgets about that..

(I guess all this info is very exotic to autoloader users..)
Best regards
Artemis

--
Artemis Kosta
Service de microscopie
FR3479 Institut de Microbiologie de la Méditerranée
31 chemin Joseph Aiguier
CS 70071 - 13402 Marseille cedex 09
France
akosta at imm.cnrs.fr
0033 491 164055
https://urldefense.proofpoint.com/v2/url?u=http-3A__www.imm.cnrs.fr_microscopie_&d=DwIDaQ&c=-35OiAkTchMrZOngvJPOeA&r=L7-zyQ-04fFCMRqzLIOnx7H0exGZHwIQe_wMPuY600I&m=Kc249O-g_SbnyG3CfngZz87oOrkHR58_oJ1WXs9R3Mo&s=Ptn3qLpNR2NdGSaylzpQvrd35cs8uO0eUw6tDuj2kfE&e=

Le 09/06/2021 à 15:48, Dokland, Terje a écrit :
> We got the Elsa and had lots of problems with it. The first two they sent us simply did not work: they would not hold the clipring in place. The third one they sent us is the ultrahigh tilt version that has the two blades that clamp the grid down. This system works well.
>
> The Elsa does hold liquid N2 for much longer, but it also takes much longer to cool down and stabilize. Most troubling is that according to my measurements the drift performance of the Elsa is not as good as the old 626, and the resulting resolution with a test sample was worse.
>
> Another annoying thing is that the Elsa holder dumps the vacuum on the column every single time it’s inserted. It should be mentioned, however, that we are having the same issue, but less frequent, with the 626, so that could be an airlock problem that Thermo Fisher has so far been unable or unwilling to fix...
>
> We used the Elsa quite a bit when our 626 was out for repair, but for the most part we prefer the 626 both for ease of use and for performance.
>
> Terje
>
>
>
>> On Jun 9, 2021, at 12:51 AM, Tobias Furstenhaupt <furstenh at mpi-cbg.de> wrote:
>>
>> Dear colleagues,
>>
>> So far we have two 626 Gatan cryoholders but we now look for a new cryo holder for our side-entry Cryo TEM (Titan Halo) to image autogrids. To my knowledge there are two companies offering those holders in the new 'toroid' design with temperature holding time of about 10h:
>>
>> - Gatan with its "Elsa" holder for one or three autogrids
>> - Simple Origins Model 200 for two autogrids
>>
>> does anybody of you know other sources? Do you have any experiences with the the Elsa or 200? We tested the latter for two weeks and it works as promised without problems.
>>
>> 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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