[RASMB] 99% versus >99% guanidine HCl

[kaltofen at uni-potsdam.de]

Hi everybody,
depending on the methods you want to use, there are huge differences  
even between "ultrapure" GuHCl from different companies and even  
between different lot-numbers from the same supplier. We do lots of  
fluorescence spectroscopy and found it worth trying different  
suppliers (Thermo and Pierce are suitable). 99% is surely ok for  
protein purification but unfortunately the impurities even in  
ultrapure GuHCl absorb UV light and emitt in the same wavelength  
region as tryptophane. Same thing holds true for urea. That should be  
considered when planning fluorescence spectroscopy.

All the best,

Sabine


> Hi,
>> 99% is typically also considered to be spectroscopically pure and is
> recommended for spectroscopic measurements/assays such as protein
> unfolding/refolding. It is typically less than 0.1 Abs at a concentration
> 6M. If you need it for e.g. inclusion body resolubilization, etc. the less
> expensive one is just as good.
> Best
> Titus.
>
> -----Original Message-----
> From: rasmb-bounces at server1.bbri.org [mailto:rasmb-bounces at server1.bbri.org]
> On Behalf Of Avi Chakrabartty
> Sent: Monday, May 17, 2010 3:25 PM
> To: rasmb at server1.bbri.org
> Subject: [RASMB] 99% versus >99% guanidine HCl
>
> Dear RASMB community,
>
> Has anybody found a real difference between 99% guanidine HCl from Aldrich
> compared to >99% guanidine HCl from Sigma?
>
> -------------------------------------------
> Avi Chakrabartty, Ph.D., Professor
> Departments of Medical Biophysics and Biochemistry,
> University of Toronto, Ontario Cancer Institute,
> MaRS Centre, 101 College St., Toronto, Ontario, M5G 1L7, CANADA
> Phone: 416-581-7553 Lab: 416-581-7555 Fax: 416-581-7555
> email: chakrab at uhnres.utoronto.ca
> --------------------------------------------
>
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Sabine Kaltofen
PhD student

Universität Potsdam
Department of Physical Biochemistry
Institute of Biochemistry and Biology
Karl-Liebknecht-Str. 24-25, Haus 25, Raum B/0.05
D-14476 Potsdam-Golm
Telefon: +49-(331)-977-5245
Email: kaltofen at uni-potsdam.de