Molecular cloning -Sambrook et al/ Tris base vs TRIZMA
"Marianne Leverone ", BIO
leverone at CHUMA.CAS.USF.EDU
Tue Jun 6 11:56:44 EST 1995
By mistake, we tried tris-HCl once and did not get polymerization; does
it have something to do with screwing up the molarity by adding
addittional ions to adjust pH? MRL
On 5 Jun 1995, 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 known first time research students
> to use this TrisHCl only to be thrown off by pH of the buffer. The mistake
> is in writing. Some people prefer to write Tris.HCl (pH X.Y) in their
> recipes, indicating that the specified pH was obtained by titrating with
> HCl. The resultant compound is a chloride salt and not hydrochloride. I
> prefer writing Tris.Cl, to avoid confusion.
> 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!
> Hiranya S. Roychowdhury
> Plant Genetic Engineering Lab.
> Box 3GL, NM State Univ.
> Las Cruces, NM 88003
> Phone: (505) 646-5785
> hroychow at nmsu.edu
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