[RASMB] AUC in the presence of 100 mg/ml Ficoll70

[Arthur Rowe]

Hi Titus

The first thing that occurs to me is "how big is your protein/whatever,  
and what are you trying to find out? Also - have you tried simply  
putting your system into 100 mg/ml Ficol? I ask because although it is  
advertised (I am sure correctly) as having "low toxicity", my own  
experience (many years ago) with trying to fractionate muscle filaments  
in Ficol was that this solvent was not exactly benign towards my  
precious samples!

Obviously in SV the Ficol 70 will sediment, and although it will be  
invisible (give or take a bit of turbidity) in the u/v, you will get  
some very weird Johnston-Ogston effects if the s values of your system  
coincide at all closely with those of the Ficol. Even if your reference  
channel contained the 100 mg/ml Ficol, you could still have problems.  
SE sounds at least as problematic - and although  you would not be  
plagued by things such as Johnston-Ogston effects,  
non-ideality/crowding effects sound daunting.

Kind regards

Arthur


On Aug 2, 2011, at 14:26, Titus M. Franzmann wrote:

> Hi,
> I was wondering if anyone could comment on whether there is a (proper)  
> way to perform either AUC SV (preferred) or EQ with 100 mg/ml Ficoll70  
> in the buffer and which would be the best way to analyze such data.
> Thanks for your assistance.
> Titus_______________________________________________
> RASMB mailing list
> RASMB at rasmb.bbri.org
> http://rasmb.bbri.org/cgi-bin/mailman/listinfo/rasmb
>
************************************************************************ 
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Arthur J Rowe
Professor of Biomolecular Technology / Director NCMH Business Centre
School of Biosciences
University of Nottingham
Sutton Bonington
Leics LE12 5RD

TEL:  0115 9516156

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