Re: [ccp4bb] Refinement with twinned data question

Dear Yuri 1) For twin refinement refmac internally changes free reflections so that twin related reflections belong to the same class (twin or working). However it would be good to generate free reflections in higher space group that would include twin and space group symmetries. 2) You

[ccp4bb] Post-doctoral position at IBS Grenoble

Post-doctoral position: structural studies of nucleotides carriers Location: IBS, Grenoble, France Starting date of the contract: latest 1^st of December 2011 A post-doctoral position is available to join the group of Pr. E. Pebay-Peyroula at IBS (Institut de Biologie Structurale, Grenoble,

Re: [ccp4bb] Refinement with twinned data question

1-So for my case, I should try and generate Rfree flags, in the higher apparent C 2 2 21 and not the real P 1 21 1, correct? 2-I noticed that if I used the output PHIC FOM data, the maps looked awesome! Too good almost... Thanks a lot On Sun, 2 Oct 2011 12:07:22 +0100, Garib N Murshudov

Re: [ccp4bb] detect dsDNA

We chewed pills with EtBr as kids in school to see if we brushed our teeth well - red colour on the edges, bad boy Poul On 01/10/2011, at 19.12, Jacob Keller j-kell...@fsm.northwestern.edu wrote: I actually looked at an EtBr MSDS a while ago, and was shocked at how benign it was. I also

Re: [ccp4bb] detect dsDNA

Jacob Keller wrote: I actually looked at an EtBr MSDS a while ago, and was shocked at how benign it was. I also heard from someone that they used to feed it to Argentinian cows routinely a few years back... Wikipedia says it was used as a trypanosomacidal - It's being discontinued not because

Re: [ccp4bb] detect dsDNA

There exists a less toxic chemical than EtBr to stain DNA: SYBR safe DNA stain (a fluorescence dye sold by a certain vendor). Another benefit is to be able to use blue light, reducing UV/VIS light exposure when handling gels. Florian On Oct 2, 2011, at 11:49 AM, Edward A. Berry wrote:

Re: [ccp4bb] detect dsDNA

There exists a less toxic chemical than EtBr to stain DNA: SYBR safe DNA stain (a fluorescence dye sold by a certain vendor). SYBR Safe is about 10X less sensitive though. I suspect that not many chemicals in the lab are less toxic/mutagenic than EthBr. The classic Ames test shows that 5 ug

Re: [ccp4bb] detect dsDNA

i wouldn't recoommend that. here is the info from somebody forwarded from our genetics department with regards to safety of that while back Sybr is just as toxic/poisonous/harmful as ethidium bromide, only far more expensive. There have been very few tests concerning it's use up

Re: [ccp4bb] detect dsDNA

There exists a less toxic chemical than EtBr to stain DNA: SYBR safe DNA stain (a fluorescence dye sold by a certain vendor). SYBR Safe is about 10X less sensitive though. Can you do the toothbrush test with SYBR Safe? I wouldn't do that. As it is considerably more hydrophobic, I'd expect

[ccp4bb] Beamtime @ SLS

=== SYNCHROTRON BEAM TIME FOR MACROMOLECULAR CRYSTALLOGRAPHY AT SLS === Proposal application deadline: Saturday, October 15, 2011 Periods: January 1, 2012 -

Re: [ccp4bb] Bicarb at low pH

You can't change the pKa of CO2, which is 6.3. Any attempt to grow bicarb complexes below pH 7.5 will be problematic due to CO2 bubble formation, which may crack the crystal. What we do in these situations is to soak crystals in a cryo solution at a higher pH for as long as practical, then

Re: [ccp4bb] Bicarb at low pH

Jacob Keller wrote: Dear Crystallographers, I would like to soak my crystals in bicarbonate (a possible substrate), but the crystals have grown--and only grow--in pH 5.2-6.0, so the bicarb/CO2 will just keep evolving out of the solution and reliquishing its hydroxyls until the pH is elevated

Re: [ccp4bb] Bicarb at low pH

You might want to consider misusing the Xe-chamber which a couple of labs and synchrotrons bought in the late 90's to derivative crystals with Xenon. Instead of flushing the chamber with Xenon you could flush it with CO2 then plunge freeze your crystals within the chamber. careful