Vijay,
Before you start with optimization make sure you do NOT have salt crystals.
Is there also protein precipitation in your drops under similar conditions?
Lithium sulphate + pH 8.5 is prone to give salt crystals.
Ammonium sulphate - high PEG concentration -> phase separation and salt
crystallization.
Better to check first to avoid wasting protein.
Enrico.
On Thu, 31 Mar 2016 08:41:48 +0200, vitul jain <[log in to unmask]>
wrote:
> Hi Vijay,
>
> To start with...
>
> For condition with 30% peg, I would suggest to use 29%, 29.5 %, 30, 30.5,
> 31, and so on....total 6 new optimised conditions with 0.5% change.
> Also, play with glycerol in the same manner. keep buffer and salt as
> constant to start.
>
> Try this to make new conditions
> http://hamptonresearch.com/make_tray.aspx
>
>
> Best
> Vitul
>
> On Thu, Mar 31, 2016 at 11:42 AM, Vijaykumar Pillalamarri <
> [log in to unmask]> wrote:
>
>> Dear Community,
>>
>>
>> I have been working on a 34kDa bacterial protein, for which I have got
>> crystals in the following two conditions.
>>
>>
>> 1) 30% PEG 400, 0.1M Caps pH-10.5, 0.5M Ammoium sulphate, 10% Glycerol
>>
>> 2) 0.1M tris pH-8.5, 0.2M Lithium sulphate, 35% 2-ethoxy ethanol
>>
>>
>> As part of optimization, I have varied PEG % (25%, 30%, 35%) and pH
>> (10.1,
>> 10.3, 10.5, 10.7, 10.9) from the first condition.
>>
>> I could see only oiling in the conditions with 35% PEG.
>>
>>
>> Please help in optimizing the condition for obtaining crystals.
>>
>>
>> Thanks in advance,
>>
>> Vijay.
>>
>
>
>
--
Enrico A. Stura D.Phil. (Oxon) , Tel: 33 (0)1 69 08 4302 Office
Room 19, Bat.152, Tel: 33 (0)1 69 08 9449 Lab
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