<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div>Hi Tobias,<br><br>Make icecream?😁 (joking)</div><div><br data-mce-bogus="1"></div><div>It is possible to filter the LN2 to avoid the contamination issues you were mentioning. Just line a normal funnel with some paper tissue (preferably lint free) and pour the LN2 through there. This should render it clean enough again to store samples or use in other instruments. <br><br>I also second the option of decanting into other vessels for passive evaporation, if you need the dewar back dry. But why don't you just leave it in there until the next user? As far as I am aware we leave whatever LN2 is left in our Stellaris dewar and simply top up for the next session. Only if there is a really long time between users, i.e. when it is too much hassle to keep it topped up, we empty and dry the dewar in a ventilated area.<br><br>Hope this helps,<br><br>Cornelia Cazey</div><div><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">Cornelia Cazey (She/Her)</span><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">Cryo-EM Facility</span><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">Centre for Structural Systems Biology (CSSB)</span><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">c/o DESY, Building 15</span><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">Notkestr. 85</span><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">22607 Hamburg</span><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">Germany</span><br><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">phone: +49-(0)40-8998-87706</span><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">email:cornelia.cazey@cssb-hamburg.de</span><br><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">"If you don't know it's impossible, it's easier to do" -Neil Gaiman</span><br><br><span style="font-size: 10pt;" data-mce-style="font-size: 10pt;">Sometimes I may send emails outside of core working hours. I do not expect you to read, or respond outside of your own working hours!</span><br><br></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><b>From: </b>3dem-request@ncmir.ucsd.edu<br><b>To: </b>"3dem" <3dem@ncmir.ucsd.edu><br><b>Sent: </b>Tuesday, 1 August, 2023 21:00:02<br><b>Subject: </b>3dem Digest, Vol 192, Issue 1<br></div><div><br></div><div data-marker="__QUOTED_TEXT__">Send 3dem mailing list submissions to<br> 3dem@ncmir.ucsd.edu<br><br>To subscribe or unsubscribe via the World Wide Web, visit<br> https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem<br>or, via email, send a message with subject or body 'help' to<br> 3dem-request@ncmir.ucsd.edu<br><br>You can reach the person managing the list at<br> 3dem-owner@ncmir.ucsd.edu<br><br>When replying, please edit your Subject line so it is more specific<br>than "Re: Contents of 3dem digest..."<br><br><br>Today's Topics:<br><br> 1. how to dispose of used liquid nitrogen? (Tobias Furstenhaupt)<br> 2. Re: how to dispose of used liquid nitrogen? (Guillaume Gaullier)<br><br><br>----------------------------------------------------------------------<br><br>Message: 1<br>Date: Tue, 1 Aug 2023 09:07:52 +0200 (CEST)<br>From: Tobias Furstenhaupt <furstenh@mpi-cbg.de><br>To: 3dem <3dem@ncmir.ucsd.edu><br>Subject: [3dem] how to dispose of used liquid nitrogen?<br>Message-ID:<br> <1593585770.304626499.1690873672619.JavaMail.zimbra@mpi-cbg.de><br>Content-Type: text/plain; charset=utf-8<br><br>Dear colleagues,<br>we own a Cryo lightmicroscope (Stellaris 8 Cryo-CLEM from Leica) that uses a 25 liter dewar for liquid nitrogen. Sometimes the session ends early and eventually we have a half-full dewar and we cannot re-use the liquid nitrogen anywhere else - either everything else is full or at some instruments we do not re-use nitrogen because of possible contaminations.<br><br>We think of blowing it out with nitrogen gas at a very well ventilated area. But this would require room alterations.<br>Therefore my question to you: How do you dispose of 10-20 liters of liquid nitrogen (that cannot be used anywhere else)? Or are we unique in our problem?<br><br>cheers<br>Tobias<br><br>----------------------------------- <br>Tobias F?rstenhaupt, PhD <br>head of Electron Microscopy <br>Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) <br>Pfotenhauerstrasse 108 <br>01307 Dresden, Germany <br><br>mail: furstenh@mpi-cbg.de <br>phone: (+49) (0)351 210-2690 <br>cell: (+49) (0)176 / 44498706 (NEW!)<br><br><br>------------------------------<br><br>Message: 2<br>Date: Tue, 1 Aug 2023 07:50:02 +0000<br>From: Guillaume Gaullier <guillaume.gaullier@kemi.uu.se><br>To: Tobias Furstenhaupt <furstenh@mpi-cbg.de>, 3dem<br> <3dem@ncmir.ucsd.edu><br>Subject: Re: [3dem] how to dispose of used liquid nitrogen?<br>Message-ID: <8838d8a7353e44c09a218fc9357b1015@kemi.uu.se><br>Content-Type: text/plain; charset="iso-8859-1"<br><br>Hello,<br><br><br>Why not donate this liquid nitrogen? If there are at your institution biochemists storing purified proteins and/or cell biologists cryo-preserving cell lines, it's likely that these people would use free liquid nitrogen if they knew where to find it. So try emailing your institution-wide list and see whether that solves your problem.<br><br><br>If you need your tank empty and dry as soon as possible for the next clean refill, one option would be to transfer its leftover nitrogen to smaller dewars that you would then advertise as free LN2 up for grabs. Of course, store these in a well ventilated room, so if nobody wants this nitrogen it can safely evaporate passively (less work for you compared to having to actively get rid of it).<br><br><br>It seems wasteful to evaporate it without at least giving other people a chance to use it.<br><br><br>I hope this helps,<br><br><br>Guillaume<br><br><br>________________________________<br>From: 3dem <3dem-bounces@ncmir.ucsd.edu> on behalf of Tobias Furstenhaupt <furstenh@mpi-cbg.de><br>Sent: Tuesday, August 1, 2023 9:07:52 AM<br>To: 3dem<br>Subject: [3dem] how to dispose of used liquid nitrogen?<br><br>Dear colleagues,<br>we own a Cryo lightmicroscope (Stellaris 8 Cryo-CLEM from Leica) that uses a 25 liter dewar for liquid nitrogen. Sometimes the session ends early and eventually we have a half-full dewar and we cannot re-use the liquid nitrogen anywhere else - either everything else is full or at some instruments we do not re-use nitrogen because of possible contaminations.<br><br>We think of blowing it out with nitrogen gas at a very well ventilated area. But this would require room alterations.<br>Therefore my question to you: How do you dispose of 10-20 liters of liquid nitrogen (that cannot be used anywhere else)? Or are we unique in our problem?<br><br>cheers<br>Tobias<br><br>-----------------------------------<br>Tobias F?rstenhaupt, PhD<br>head of Electron Microscopy<br>Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)<br>Pfotenhauerstrasse 108<br>01307 Dresden, Germany<br><br>mail: furstenh@mpi-cbg.de<br>phone: (+49) (0)351 210-2690<br>cell: (+49) (0)176 / 44498706 (NEW!)<br>_______________________________________________<br>3dem mailing list<br>3dem@ncmir.ucsd.edu<br>https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem<br><br>VARNING: Klicka inte p? l?nkar och ?ppna inte bilagor om du inte k?nner igen avs?ndaren och vet att inneh?llet ?r s?kert.<br>CAUTION: Do not click on links or open attachments unless you recognise the sender and know the content is safe.<br><br><br><br><br><br><br><br><br>N?r du har kontakt med oss p? Uppsala universitet med e-post s? inneb?r det att vi behandlar dina personuppgifter. 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