Tascimate can be used as the cryo as well. I have had experience with crystals in similar condition and moved the crystals to a 20% increased Tascimate solution and they froze well.
I agree with Ezra, room temperature mount your crystal before freezing. It is the only way to know the true problem. Kelly ******************************************************* Kelly Daughtry PhD Candidate Department of Physiology and Biophysics Boston University School of Medicine 590 Commonwealth Ave R 390 Boston MA, 02215 (P) 617-358-5548 ******************************************************* On Tue, Jan 26, 2010 at 1:25 PM, Marcus Winter <marcus.win...@oxford-diffraction.com> wrote: > Dear Zhiyi, > > > Ezra is exactly right, of course. The Oxford Diffraction PX Scanner > system can assess the diffraction qualities of (putative) protein > crystals in situ - in the crystallisation plate. So, directly, you > would discover if your 'big and beautiful' crystals actually diffract > well... in their mother liquor under ambient conditions and before the > addition of any cryo-protect. Do you have a friend or neighbour with > a PX Scanner ? If not, please feel most welcome to contact > Oxford Diffraction: we would be pleased to assist if at all possible. > > > Good Luck and Best Wishes, > > Marcus Winter. > > www.oxford-diffraction.com > > > > > -----Original Message----- > From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of > Ezra Peisach > Sent: 26 January 2010 16:01 > To: CCP4BB@JISCMAIL.AC.UK > Subject: Re: [ccp4bb] Crystal rescue > > First you need to establish if it is your cryo conditions or the > crystals. Depending where you are - they might have the equipment to do > > a wet mount - without freezing. Yes the crystal will not last - but > then you know if the problem is in the > crystal. If it is - you need better crystals. If it is the cryo - you > need to work on that. Tacsimate is mixture of alot of different > compounds - but the smears are too close together to be a small salt > crystal on top... > > Good luck, > > Ezra > > On 1/26/2010 10:42 AM, Zhiyi Wei wrote: >> Dear all, >> >> I got a problem with my crystals. I have two total different proteins >> that both can be crystallized in the condition with PEG3350 and > Tacsimate >> (although the concentrations are different) with different shapes. The >> crystals look big and beautiful. However, when I test them in > synchrotron, >> both of these two types of crystals showed poor diffractions. As > showed in >> the attached diffraction image, the diffraction is up to ~4 A but > smear in >> one direction while<8 A in the other direction. The interesting thing > is >> that the diffraction pattern is similar for all crystals (from two > different >> proteins) that I tested without exception although they belong to > different >> space groups. So, I wonder whether these kind of pattern is caused by >> Tacsimate (I don't know what it is) and how to rescue these crystals. > Any >> suggestions or comments? >> >> Thanks a lot! >> >> Best, >> Zhiyi >> >
