We put a supply line of compressed air (not sure how dry this is) in the dewar to wam it up and dry it out. We leave this running overnight, and this seems to result in the dewars being dry enough for later use. We haver never bothered to weight the dewars before and after use etc, so can't comment on how well this really dries the dewars. Icing seems in our case more dependent on manipulation of the samples and the pucks (we think unipucks cause more problems than pucks that hold the pin in a vial, but can't prove that). And maybe on how clean the LN2 is in the sample changer dewars (at home and at the synchrotron).
Johan On 17 July 2013 12:34, Phil Evans <p...@mrc-lmb.cam.ac.uk> wrote: > > In response I felt I had to post the low-tech version (not mine) > Phil > > > > On 16 Jul 2013, at 11:57, Edward Lowe <edward.l...@bioch.ox.ac.uk> wrote: > > At Elspeth's request, here's a link to a picture of the rack we use for > drying out shipping dewars. > > https://www.dropbox.com/s/8ber2iikra9x73y/2013-02-21%2013.39.38.JPG > > Very simple and both we and the Lea group here have found it to make a > huge difference the the effectiveness and longevity of our dewars. > > Ed. > > -- > Dr. E.D. Lowe > Department of Biochemistry > University of Oxford > South Parks Road > Oxford, UK > OX1 3QU > > e:edward.l...@bioch.ox.ac.uk > t: +44 (0) 1865 613288 > f: +44 (0) 1865 613201 > > > > > On 12/07/2013 14:27, "Edward Snell" <esn...@hwi.buffalo.edu> wrote: > > Ditto - I was always impressed with the contraption in the Garman lab > which, if I remember correctly, is made of a thick block of wood and some > plumbing pipes. It is designed to hold empty open Dewars inverted so they > could dry. > > Edward Snell Ph.D. > Assistant Prof. Department of Structural Biology, SUNY Buffalo, > Senior Scientist, Hauptman-Woodward Medical Research Institute > 700 Ellicott Street, Buffalo, NY 14203-1102 > Phone: (716) 898 8631 Fax: (716) 898 8660 > Skype: eddie.snell Email: esn...@hwi.buffalo.edu > Telepathy: 42.2 GHz > > Heisenberg was probably here! > > > -----Original Message----- > From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of > Ginell, Stephan L. > Sent: Friday, July 12, 2013 12:45 AM > To: CCP4BB@JISCMAIL.AC.UK > Subject: Re: [ccp4bb] frosted crystals during storage in pucks > > My experience with xtals frosting in LN2 either in a dewar, while > freezing, or in pucks, has been because the LN2 was contaminated with ice > crystals The fog you see above your dewar when freezing xtals is frozen > water vapor...it will fall and collect in the LN2 and also deposit on the > xtals. Dewars filled with recycled LN2 get contaminated with ice. Dewars > dried upside down allow the cold gas to flow out and warm moist air to > flow in and the water to condense inside the dewar (basic physics). To > dry shipping dewars keep up right while warming. > Steve > > Sent from my iPad > > On Jul 11, 2013, at 5:25 PM, "Nathaniel Clark" > <nathanielcl...@gmail.com<mailto:nathanielcl...@gmail.com>> wrote: > > At our last synchrotron trip, the beamline staff suggested that the > problem was due to moisture accumulation in the dry shipper. They > recommended storing them inverted (for a few weeks, if I recall), and/or > putting a supply of dry air in the dewer. Haven't tried it yet! > Nat > > > On Thu, Jul 11, 2013 at 5:08 PM, <Rain Field> > <rainfiel...@163.com<mailto:rainfiel...@163.com>> wrote: > Hi All, > We found if the crystals are storaged in pucks for 3-4 days in shipping > dewar (with liquid nitrogen), they are almost frosted. > Although I can wash them with liquid nitrogen, but it's not convenient to > do that for each crystals. > I doubt it's because the humid air in North West America. > Does anyone has an idea how to avoid this? > Thank you! > > > -- Dr. Johan P. Turkenburg X-ray facilities manager York Structural Biology Laboratory University of York Phone (+) 44 1904 328251 York YO10 5DD UK Fax (+) 44 1904 328266 Note new email address johan.turkenb...@york.ac.uk
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