Hi,
you changed something, and although it seems very small a change, this
can make a difference between crystals and non-crystals. And removing
the His-Tag is not a small change, since it influences the net charge.
The first thing to try is micro and macro-seeding. If they don't work,
you may need to screen again.
Best,
Tim
On 07/14/2014 01:44 PM, dusky dew wrote:
> Dear all,
> I am trying to reproduce some protein crystals. The protein I am getting
> after cutting the his tag is very pure. I am using the reported protein
> concentration. The cofactor and EDTA needs to be added externally. The
> condition has calcium acetate, peg 4k and sodium acetate buffer.
> Unfortunately I am getting oil separation and light ppt. I have no clue
> what is wrong. Please help!
>
--
Dr Tim Gruene
Institut fuer anorganische Chemie
Tammannstr. 4
D-37077 Goettingen
GPG Key ID = A46BEE1A
|