Re: [ccp4bb] crystallization incubators

2008-06-22 Thread Michael Hothorn
Dear Alexandra, I bought this one recently and it is very nice. Very low vibration and enough space for about 25 24-well plates plus maybe 50 96-well plates. The only problem I had is that in my case the temperature reading on the external LCD display is slightly off compared to the 'real'

Re: [ccp4bb] How many reflections for Rfree?

2008-06-22 Thread Ian Tickle
Hi Sam As I said, if you have NCS (doesn't matter whether you restrained it or not) you need to be aware that the results may not be accurate, because there are well-documented ways in which NCS can affect Rfree completely unpredictably. With that in mind, if you refer to our Acta D paper

Re: [ccp4bb] query on DNA-protein complex preparation for crystallization

2008-06-22 Thread E rajakumar
Hi Artem Evdokimov Thank you for the mail. I have synthesized DMT-on oligos in our laboratory. Deprotection was performed treating with ammonium hydroxide for 15 hours at 55C. Then, DMT-on oligo was separated from off using RPHPLC. DMT was cleaved by treating with 20% glacial acetic acid for one

Re: [ccp4bb] query on DNA-protein complex preparation for crystallization

2008-06-22 Thread William Scott
Check the purity of the DNA in solution: A(260 nm)/A(280) = 1.8 for fully deprotected DNA, and you should see a nice clean simple curve with a peak very close to 260 nm. Check it on a denaturing gel. Smearing indicates incomplete deprotection. This is usually the cause of solubility

Re: [ccp4bb] query on DNA-protein complex preparation for crystallization

2008-06-22 Thread E rajakumar
Hi Thank you for the mail. It seems your correct. A(260 nm)/A(280) of one oligo is around 1.0 and peak is around 272. Other oligo's(260 nm)/A(280) is around 1.5. Can I know what is the absorbance peak of base protecting N-benzoyl group. Is it possible to do deprotection of base after mixing

Re: [ccp4bb] query on DNA-protein complex preparation for crystallization

2008-06-22 Thread Artem Evdokimov
I think that at this point you're better off looking at a professional literature. For example: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=102833 Artem -Original Message- From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of E rajakumar Sent: Sunday, June 22,