The crystal also needs to be cooled during data collection. I would really go for the glass-capillaries. Herman
-----Original Message----- From: CCP4 bulletin board [mailto:[email protected]] On Behalf Of Edward A. Berry Sent: Friday, February 18, 2011 3:56 PM To: [email protected] Subject: Re: [ccp4bb] Freezing crystals in a contained system Cooling will be extremely slow in the mitegen sheath - remember in glass capillaries the crystal is right on the wall of the cap, stuck on with a bit of mother liquor. In the mitegen system the crystal is on a pin in the center of the sheath, so thermal contact with the outside will be through the gas layer between it and the wall (compare your double-pane energy-saving glass windows) or through the base, up the pin, through the yellow plastic foil to your crystal. Not to disourage you from trying, but you might want to use a stronger cryoprotectant than usual. eab Colin Nave wrote: > Becky > Do you have the nitrogen stream co-linear with the capillaries, with > the specimen near the capillary end and therefore near the nitrogen > stream exit? This might help to minimise turbulence - though nowadays > other bits of kit fight to occupy this space. > Regards > Colin > >> -----Original Message----- >> From: CCP4 bulletin board [mailto:[email protected]] On Behalf Of > R >> Conners, Biochemistry >> Sent: 17 February 2011 17:03 >> To: [email protected] >> Subject: [ccp4bb] Freezing crystals in a contained system >> >> Dear all, >> >> We are working on a Category 3 protein which must be contained so we >> have our crystals mounted in a loop and then covered with a plastic >> Mitegen cover which is glued in place. We're currently collecting at >> room temperature, but wondered if anyone has any experience of using >> a contained system at low temperatures? Any attempts I've had so far >> at freezing through either the plastic or a glass capillary have >> resulted in formation of ice on the surface so it is not even >> possible to see the crystal to centre it. >> >> Best wishes, >> >> Becky >> >> ------------------------------------------------- >> Dr Becky Conners >> School of Biochemistry >> University of Bristol, UK >> >> http://www.bris.ac.uk/biochemistry/brady >> [email protected] >> 0117 3312149 >
