Re: protein solution

[Ricardo Aparicio <aparicio@lnls.br>]

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Lan Zhou wrote:

>
> I have a very-well expressed protein.  It is fine at both 4c and room
> temperature (rt) as long as its concentration is below 1 mg/ml.  If I
> concentrate the protein to 4 mg/ml or even 20 mg/ml or so, they are still
> fine at 4c.  However, the protein solutions become very cloudy if I
> transfer them to rt or 16c.  The protein solutions will turn to clear
> again after they are put back to 4c for a while.
>
> Is there anyone who has experience this before ?  What could be the
> problem ?  Does it mean something wrong with the protein folding ? Is
> there any suggestion ?

I'm not an expert neither a Biologist but I have 2 ideas:
1- did you test your solutions without any protein? It's a good idea to check
them at 4 oC and room temp.
2 -  try to change other variables like salt concentration in your protein
solutions

Good luck,

Ricardo


===========================================================
Ricardo Aparicio
PhD Student at the Brazilian Synchrotron LNLS - http://www.lnls.br
Protein Crystallography Group
Phone +55(19)2874520 / Fax +55(19)2874632