We used to use FTS-cooler for stable temperatures in Laue-experiments on protein crystals in capillaries. Check out BioCARS at the APS for this device. http://cars9.uchicago.edu/biocars/pages/timeresolved.html It has a big opening for constant air flow and temperature along the capillary and it can go to sub 0 deg C.
Marius > Matthew, > > I have not had any problem with our Cryojet XL (90 - 300 Kelvin), it > is > very stable at sub-zero temperatures, I checked it over a longer > period > using a highly sensitive electronic device. Also, you can buy the > Cryojet HT that can be operated from 90 – 490 Kelvin! > The heaters will be okay for both devices. > > But more important, coaxial mounting does not help unless the > capillary > is really short! If the capillary is to long, water will again > collect > at the point closest to the nozzle, especially if the data collection > takes more than one or two hours! > > I am not aware of any cheaper devices that deliver a stable > temperature > over a prolonged time-span. > > - J. - > > > [EMAIL PROTECTED] wrote: > > Hi Patrick - > > Many cryosystems (definitely the Cryojet, and I believe the > Cryostream) can > be set to run at any temperature between room temp and liquid > nitrogen > temp. I'm not sure of the temperature stability at temps > 0 C, and > you > might burn out the heaters prematurely if you do this all the time, > but it > should work. Then you just need to move the nozzle so it's coaxial > with > your goniostat's rotation axis, and aim the capillary down the > nozzle. You > could probably even move the capillary *inside* the cryo nozzle a > bit, so > only the bit with the crystal is in the free stream. > > It's not a cheap solution, but you've almost certainly got a > cryosystem > already... > > - Matt > > -- > Matthew Franklin , Ph.D. > Senior Scientist, ImClone Systems > 180 Varick Street, 6th floor > New York, NY 10014 > phone:(917)606-4116 fax:(212)645-2054 > > Confidentiality Note: This e-mail, and any attachment to it, > contains > privileged and confidential information intended only for the use of > the > individual(s) or entity named on the e-mail. If the reader of this > e-mail > is not the intended recipient, or the employee or agent responsible > for > delivering it to the intended recipient, you are hereby notified that > reading it is strictly prohibited. If you have received this e-mail > in > error, please immediately return it to the sender and delete it from > your > system. Thank you. > >> CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> wrote on 07/10/2007 02:07:37 >> PM: >> >> >>> Jeroen brings up a good point. Back in the old days, around 5 B. C. >>> (Before Cryo), we would use a chilled air generator to blow a stream >>> of cold air along the capillary axis to keep the crystals just above >>> their freezing point--it made a huge difference in crystal lifetime. >>> I recall a colleague devising an apparatus from a 50 ml conical >>> tube. The bottom was cut off and cold air was blown in from the >>> other end. Windows were cut in either side to allow the beam to pass >>> & covered in mylar. This way the entire capillary was contained >>> within the cold tube, so no temperature gradients formed along the >>> length of the capillary (temp gradient => distillation => dead >>> crystal). Later, we purchased a very clever goniometer head from >>> Nonius that had a plastic cylinder attached to goniometer head, with >>> a swivel, so the hose supplying cold air didn't get tangled during >>> data collection... >>> >>> I've often thought duplicating this apparatus when we encounter cryo >>> problems, but I'm always stymied when trying to find a cheap and >>> simple source of cold air. Any bright ideas? >>> >>> >> >> > > -- > Jeroen Raymundus Mesters, Ph.D. > Institut fuer Biochemie, Universitaet zu Luebeck > Zentrum fuer Medizinische Struktur und Zellbiologie > Ratzeburger Allee 160, D-23538 Luebeck > Tel: +49-451-5004070, Fax: +49-451-5004068 > E-mail: [EMAIL PROTECTED] > Http://www.biochem.uni-luebeck.de > Http://www.iobcr.org > Http://www.opticryst.org > -- > If you can look into the seeds of time and say > which grain will grow and which will not - speak then to me (Macbeth) > -- PD Dr. habil. Marius Schmidt Physikdepartment E17 Technische Universitaet Muenchen James Franck Strasse 85747 Garching/Germany email: [EMAIL PROTECTED] http://users.physik.tu-muenchen.de/marius/ phone: +49-(0)89-2891-2550 fax: +49-(0)89-2891-2548
