Molecular cloning -Sambrook et al/ Tris base vs TRIZMA

Pamela Norton pnorton at
Tue Jun 6 10:57:05 EST 1995

In article <Pine.A32.3.91.950605144847.56848B-100000 at paris>,
hroychow at NMSU.EDU (Hiranya Roychowdhury) wrote:

> On 5 Jun 1995, T.S. Pillay wrote:
> > In the electrophoresis section in Molecular Cloning by Sambrook et al 
> > (a.k.a. the "Maniatis")  it says not to use TRIZMA for SDS PAGE
> > electrophoresis buffers but Tris Base which should be pH'd to the
> > appropriate pH instead of using a mixture of Trisbase and Tris-HCl.  Does
> > anyone know the reason for this.
> > 
> But I thought Tris base and Trizma were the same. The compound used for
> electrophoresis is tris(hydroxymethyl)aminomethane which, from Sigma,
> comes as TRIZMA (base). The TrisHCl is simply the hydrocloride of the
> above and is extremely acidic. 
> 	I have never come across any protocol where the Tris buffer is
> prepared by mixing Tris base and hydrochloride to obtain a specific pH. I 
> am not sure what the authors in Sambrook et al. meant, but I will not be 
> surprised if it is a mistake. There are a few very obvious yet serious 
> mistakes in that manual. The question is that whether, by using Trizma 
> base, anybody has encountered any problem in SDS-PAGE!
				TIn response to the above:


    I wasted over a month trying to figure out what the heck had gone wrong
with my SDS-PAGE gels after setting up a new lab. Gels ran slowly, with odd
voltage/current ratios, bands were fuzzy, resolution was poor in a critical
mol. weight range (ca. 60 kDa). Problems were solved by formulating all the
buffers with Tris base (we get it from Gibco/BRL, no affiliation,
presumably other sources work as well) instead of Trizma. I too was
skeptical but tried this as a last resort based on the comment in Sambrook
et al. The difference was astounding. 
    However, I still don't know the correct answer to the original poster's
question, but I believe the Cl- ion concentration is the critical thing. 

    Hope this helps prevent someone from wasting their time,

													Pam Norton

Pamela A. Norton, Ph.D.          Assistant Professor of Medicine
Thomas Jefferson University
Philadelphia, PA 19107           p_norton at

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