MiTeGen (www.mitegen.com) sells a RT device - plastic capillary to put
over loop... I do not know how well it would work for a long data
collection - but people here have used it to evaluate their crystals....
Ezra
On 1/27/2010 3:58 AM, Flip Hoedemaeker wrote:
> Zhiyi,
>
> You can use a thin cap over your cryo loop, just put a drop of mother
> liquor in the top, place over the loop and make it airtight at the
> base. Not sure who sells these things though, I guess you can make it
> from a capillary too. Then remove the cryo stream or put it at a temp
> above freezing, say 253K.
>
> Flip
>
> Zhiyi Wei wrote:
>> Thanks for so many quick responses!
>>
>> Actually, I have test several different cryo-protectants, including
>> glycerol, EG, and PEG400. I did not see much differences between these
>> cryo conditions. So, I choose glycerol.
>>
>> I would like to test my crystals in RT. But I don't know how to do
>> this. Just mount crystal to the X-ray machine without cryo stream? Or
>> I should use capillaries?
>>
>> Zhiyi
>>
>> On Wed, Jan 27, 2010 at 5:45 AM, Kelly Daughtry <[log in to unmask]> wrote:
>>> 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
>>> <[log in to unmask]> 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:[log in to unmask]] On Behalf Of
>>>> Ezra Peisach
>>>> Sent: 26 January 2010 16:01
>>>> To: [log in to unmask]
>>>> 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
>>>>>
>>
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