Nonidet P40 and Bradford
Belscotia
I used to use NP-40 for solubilizing my protein extracts, but now use
IGEPAL-CA 630 and everything still seems OK. I don't know about the
Bradford assay but BIO-RAD do a protein determination kit which works
well in the presence of many different detergents (according to bio-rad
anyway!) I have used this kit in the presence of 0.5% NP-40 and 0.5%
deoxycholate with good results.
I am NOT employed/sponsered by BIO-RAD!
bye
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Dr. Fernando Rodriguez-Pascual
Have any of you experienced problems in performing protein
determinations by Bradford using extracts containing 0.5% Nonidet P40. I
mean, whether it is compatible with the Bradford reagent and up to which
concentration. In former times I used to have no problems for that but
now I find that anyhow it affects the assay.
By the way, Sigma is not longer purchasing Nonidet P40, but a
"chemically indistinguible from it" compound (as Sigma) called IGEPAL-CA
630. Do you know if it is really the same? Have you found problems by
using this new nonionic detergent?
Chao
Fernando
--
#############################################
Dr. Fernando Rodríguez Pascual
Department of Pharmacology
Johannes Gutenberg University
Obere Zahlbacher Str. 67
D-55101 Mainz, Germany
Tf. +49 (6131) 39 3 68 36 or 39 3 32 45
Fax. +49 (6131) 39 3 66 11
email: frod...@mail.uni-mainz.de
#############################################
Dr. Fernando Rodriguez-Pascual
>
> Belscotia schreef:
>
> > Hi there
> > I used to use NP-40 for solubilizing my protein extracts, but now use
> > IGEPAL-CA 630 and everything still seems OK. I don't know about the
> > Bradford assay but BIO-RAD do a protein determination kit which works
> > well in the presence of many different detergents (according to bio-rad
> > anyway!) I have used this kit in the presence of 0.5% NP-40 and 0.5%
> > deoxycholate with good results.
> > I am NOT employed/sponsered by BIO-RAD!
> >
> > bye
> >
> >
>
> One is a Bradford variant. It is the more sensitive but is incompatible with
> detergents, dyes or strong alkali.
> The other (they call it DC assay) is a Lowry variant. It is compatible with most
> detergents, but not with thiols (it can, however, be made compatible with
> thiols).
Hi Henk,
How can it be made compatible with thiols?
> Hope this helps.
>
> --
>
> H. Veldman
> Laboratory for Experimental Neurology (NMZ)
> Room G 02.320
> University Medical Center Utrecht (AZU)
> P.O. Box 85500
> 3508 GA UTRECHT
> The Netherlands
> Tel: +31 30 2507565
> Fax: +31 30 2542100
> E-mail: H.Ve...@lab.azu.nl
Wolfgang Schechinger
Including the detergent into the standard
solutions reduces the errors.
If this doesn't work with your system, you could precipitate the
proteins in your sample (e.g. with TCA or try a "reverse"
phenol/chloroform extraction and keep the pellet) and wash out the
detergent.
Wolfgang
> From: "Dr. Fernando Rodriguez-Pascual" <frod...@mail.uni-mainz.de>
> Subject: Nonidet P40 and Bradford
> Date: Mon, 10 Jan 2000 15:13:24 +0200
> Organization: Johannes Gutenberg-Universitaet Mainz, Germany
> Reply-to: frod...@mail.uni-mainz.de
> To: met...@hgmp.mrc.ac.uk
> Hi all,
>
> Have any of you experienced problems in performing protein
> determinations by Bradford using extracts containing 0.5% Nonidet
> P40. I mean, whether it is compatible with the Bradford reagent and
> up to which concentration. In former times I used to have no
> problems for that but now I find that anyhow it affects the assay.
> By the way, Sigma is not longer purchasing Nonidet P40, but a
> "chemically indistinguible from it" compound (as Sigma) called
> IGEPAL-CA 630. Do you know if it is really the same? Have you found
> problems by using this new nonionic detergent?
>
> Chao
>
> Fernando
> --
> #############################################
> Dr. Fernando Rodríguez Pascual
> Department of Pharmacology
> Johannes Gutenberg University
> Obere Zahlbacher Str. 67
> D-55101 Mainz, Germany
> Tf. +49 (6131) 39 3 68 36 or 39 3 32 45
> Fax. +49 (6131) 39 3 66 11
> email: frod...@mail.uni-mainz.de
> #############################################
Dr. Wolfgang Schechinger, Pathobiochemistry Dept.
University of Tuebingen, Germany
email: wolfgang.s...@med.uni-tuebingen.de
wwWait: http://www.medizin.uni-tuebingen.de/~wgschech/start.htm
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Henk Veldman
> Hi there
> I used to use NP-40 for solubilizing my protein extracts, but now use
> IGEPAL-CA 630 and everything still seems OK. I don't know about the
> Bradford assay but BIO-RAD do a protein determination kit which works
> well in the presence of many different detergents (according to bio-rad
> anyway!) I have used this kit in the presence of 0.5% NP-40 and 0.5%
> deoxycholate with good results.
> I am NOT employed/sponsered by BIO-RAD!
>
> bye
>
>
Bio-Rad sells two assays:
One is a Bradford variant. It is the more sensitive but is incompatible with
detergents, dyes or strong alkali.
The other (they call it DC assay) is a Lowry variant. It is compatible with most
detergents, but not with thiols (it can, however, be made compatible with
thiols).
Li Jingsong
rogier
BCA kit (sold by many different companies) works OK with NP40
Rpgier
Jim Kami
spermatocide)
They are all trade names for the same compound.
ref. Merck Index ed. 10 #6601
Jim Kami
Blue Rose Biotech
Dr. Fernando Rodriguez-Pascual
compound?
I think it is wrong...
Fernando
Susanne Rohrer
From the Sigma Product data sheet:
> Nonidet P40 = Tergitol = Nonylphenol series
C9H19-Ph-O(Ch3CH2O)x-H
I understand x = about 40
> IGEPAL-CA630= Triton X-100 = Octoxynol - 9 (Octylphenol series)
(CH3)3C-CH2-C(CH3)2-Ph-(OCH2CH2)x-OH
where Ph= Phenyl and x= nr ethylene oxide units, i.e. x=9-10
>
> They are all trade names for the same compound.
> ref. Merck Index ed. 10 #6601.
almost all.
Jim Kami
quote from the reference I cited. Came as a suprise to me when I looked
this up some years ago.
Jim
"Dr. Fernando Rodriguez-Pascual" wrote:
> Is it really true that Nonidet P40 and Triton X-100 are the same
> compound?
> I think it is wrong...
>
> Fernando
>
> Jim Kami wrote:
> >
> > Nonidet P40 = IGEPAL-CA = Triton X-100 = Octoxynol - 9 (common
> > spermatocide)
> > They are all trade names for the same compound.
Mark Solomon
part of their structures, each has a number of repeats of
polyoxyethyleneglycol. NP-40 has 9 repeats, whereas Triton X-100 is a
mixture of compounds with 9 and with 10 repeats.
Mark Solomon
Yale University
In article <387F69CF...@ucdavis.edu>, Jim Kami <jak...@ucdavis.edu> wrote:
: I'm not in the area of detergent/surfactant development. I can only
: > >
Mano
I have had the same question in the past, but did not investigate it too
much.
NP-40 or IGEPAL works equally well for me. When NP40 was no longer
available, I tried IGEPAL and it worked fine, but I did not compare the two
for efficiency, since they are "chemically" identical anyways.
In terms of the Bradford assay from BIO RAD, it also works fine. I use
1-3 microlitres and never seen a problem.
Take care,
Mano