Hi Raji,
i the kit i used for this purpose was from Pierce it's call Protein BCA RAC
assay. BCA : for the colorimetric parts, en ad the RAC is for Reducing agent
compatibility. This RAC is also efficient with detergent. (according my
remember)
But you if you use at the same time detergent and Reducing Agent, it's
inefficient.
http://www.piercenet.com/product/bca-protein-assay-reducing-agent-compatible
If you use this one, it could be costless to buy the microplate oriented kit.
(you can use also without microplate and you have more experiment in the same
box)
Nicolas
________________________________________
De : CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] de la part de Ho Leung Ng
[h...@hawaii.edu]
Envoyé : vendredi 14 février 2014 01:58
À : CCP4BB@JISCMAIL.AC.UK
Objet : Re: [ccp4bb] Determining concentration of membrane protein
Hi Raji,
There are also some proprietary stains such as the "660 nm" (can't they
think of a better product name?) stain from Pierce that are detergent
compatible. I used this briefly with success when comparing against Abs 280 nm.
Ho
Ho Leung Ng
University of Hawaii at Manoa
Assistant Professor, Department of Chemistry
h...@hawaii.edu<mailto:h...@hawaii.edu>
Date: Thu, 13 Feb 2014 10:06:12 -0500
From: Raji Edayathumangalam <r...@brandeis.edu<mailto:r...@brandeis.edu>>
Subject: Determining concentration of membrane protein
Dear CC4BBers,
I am trying to figure out what is the best way to determine the protein
concentration of my membrane protein. My purified membrane protein is in
20mM Tris pH 7, 150mM NaCl and 0.02% DDM (CMC of DDM=0.0076%).
After reading the friendly manuals and searching online, I've learned that
detergents interferes with assays like Bradford but can't find good
descriptions of what works best. For now, I am trying to estimate
concentration from absorbance at 280nm and using molar extinction
coefficients based on aromatic amino acids, but again suspect detergent
interference. I would like to know what other folks working on membrane
proteins are doing.
Thanks very much.
Raji
