[ccp4bb] is it Ok to freeze

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).

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 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 having

Re: [ccp4bb] is it Ok to freeze

:[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 probably yes

Re: [ccp4bb] is it Ok to freeze

? 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 small molecules, then the opinion for the last 15 years at least

Re: [ccp4bb] is it Ok to freeze

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 model

Re: [ccp4bb] is it Ok to freeze

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

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 structural analysis, pretty well all datasets are collected at 100K unless the crystals fall apart at low T, or if the

Re: [ccp4bb] is it Ok to freeze

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

Re: [ccp4bb] is it Ok to freeze

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 structural analysis, pretty well all datasets are collected at 100K unless the crystals

Re: [ccp4bb] is it Ok to freeze

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.AC.UK Subject: Re: [ccp4bb] is it Ok to freeze

Re: [ccp4bb] is it Ok to freeze

, 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.AC.UK Subject: Re: [ccp4bb] is it Ok to freeze Hi

Re: [ccp4bb] is it Ok to freeze

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

Re: [ccp4bb] is it Ok to freeze

... 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

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 picture

Re: [ccp4bb] is it Ok to freeze

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

Re: [ccp4bb] is it Ok to freeze

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.