Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Santarsiero, Bernard D.
Dick Dickerson tried to do the same thing at Caltech around the same time. The major problem with cooling equipment was that the Picker goniometer had lots of metal in it, and each of the metal pieces cooled and contracted differently, so the alignment was always off. Nice idea, but not useful. Tha

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Jim Pflugrath
I've been in that cold room / hutch. I never heard of it being flushed with LN2. I think that is just to make the room sound cooler. Jim On Thu, 19 Jun 2008, Mischa Machius wrote: Sadly, I have never seen the room being used. Perhaps one of the 'older' Martinsrieder on the forum has seen it

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Mischa Machius
Sadly, I have never seen the room being used. Perhaps one of the 'older' Martinsrieder on the forum has seen it. MM On Jun 19, 2008, at 12:11 PM, Klaus Futterer wrote: "... room that was lined with insulated steel walls and that could be flushed with liquid nitrogen." I'm trying to pictur

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Klaus Futterer
"... room that was lined with insulated steel walls and that could be flushed with liquid nitrogen." I'm trying to picture this ... did you guys have some kind of LN2- proof SCUBA diving equipment to work in there? Klaus ---

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Mischa Machius
Ha, everyone seems to be bragging about how far back cryo- crystallography really goes. In that vain, I'd like to mention that, in Martinsried, we had a room that was lined with insulated steel walls and that could be flushed with liquid nitrogen. It was requested (demanded, really...) by Ro

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Pietro Roversi
Well everyone, talking of early applications of cryocooling to X-ray crystallography, what about Sten Samson's marvellous helium cryostat which was operational at Caltech since the end of the 1970s and used to reach temperatures around 20 K routinely , see for example: Proc Natl Acad Sci U S A

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Santarsiero, Bernard D.
e the >> contribution from thermal motion. >> >> -- Ian >> >>> -Original Message- >>> From: [EMAIL PROTECTED] >>> [mailto:[EMAIL PROTECTED] On Behalf Of harry powell >>> Sent: 19 June 2008 14:05 >>> To: Remy Loris >>

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Diana Tomchick
if you're into valence density deformation maps, again in order the minimise the contribution from thermal motion. -- Ian -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of harry powell Sent: 19 June 2008 14:05 To: Remy Loris Cc: CCP4BB@JISCMAIL.A

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Ian Tickle
14:05 > To: Remy Loris > Cc: CCP4BB@JISCMAIL.AC.UK > Subject: Re: [ccp4bb] is it Ok to freeze > > Hi > > Without wishing to start an argument, I've been checking with > some of my colleagues who are chemical crystallographers - > the reply I get is that, for routine stru

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Marius Schmidt
This fellow below is presumably and Indian, writing in English at a German University, a very confused new generation researcher, indeed. Maybe this will help: S.Jayashankar (Ein wenig verwirrter Forscher der neuen Generation) Forschungsstudent Institut fuer Biophysikalische Chemie Medizinische Sc

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread harry powell
Hi Without wishing to start an argument, I've been checking with some of my colleagues who are chemical crystallographers - the reply I get is that, for routine structural analysis, "pretty well all datasets are collected at 100K unless the crystals fall apart at low T, or if the cryostre

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Remy Loris
Typically crystals of small organic compounds do not require freezing as there are no solvent channels. They do in general not suffer from radiation damage at room temperature the way protein crystals do. Occasionally they are mounted in a capillary instead of simply glueing them to a goniomete

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread harry powell
Hi I just noticed I scrambled that first paragraph. I didn't intend to imply you should be able to see your referees (or their criteria) at least some of the time. It should have read something more like- yes, both of those. Plus "freezing out" multiple conformations so that you can mode

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread harry powell
tion in B factors, reduction in radiation damage, anything else? Colin -Original Message- From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of harry powell Sent: 19 June 2008 10:12 To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] is it Ok to freeze Hi If you mean organic

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread Nave, C (Colin)
rd [mailto:[EMAIL PROTECTED] On Behalf Of harry powell Sent: 19 June 2008 10:12 To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] is it Ok to freeze Hi If you mean organic small molecules, then the opinion for the last 15 years at least is pro

Re: [ccp4bb] is it Ok to freeze

2008-06-19 Thread harry powell
Hi If you mean organic small molecules, then the opinion for the last 15 years at least is probably "yes, unless you know you'll have a phase change". Most small molecule crystals don't have the same problems with needing cryoprotectants as macromolecules, due in large part to not havin

[ccp4bb] is it Ok to freeze

2008-06-19 Thread Jayashankar
Dear Scientists and Friends, I am not sure, whether organic crystals need to be in cryo stream necessarily during data collection from an in house xray machine . How most of the organic crystals have been solved mostly? -- S.Jayashankar (A bit confused new generation researcher). Research