Okay, Okaaaay!. Here's the recipe for Non ppt 10x TBE

Jim Owens jow at helix.nih.gov
Tue May 31 16:09:14 EST 1994


In article <2s59as$smd at mserv1.dl.ac.uk> I.B. Vipond,
mbibv at s-crim1.dl.ac.uk writes:
>	162g 	Tris
>	27.5g 	Borate
>	9.5g  	EDTA
>
>	Make up to 1 litre with ddH20.

In article <2s5k9u$9rf at news.bu.edu> Richard Near, rocket1 at bu.edu writes:
>From the recipe, I wonder if this is really "TBE" at all?
>Hard to say without the actual make-up of the solids used,
>but it seems to me that the proportions are wrong??

Richard Near is correct.  The pH would be significantly higher than usual
for TBE, especially if "Borate" means sodium tetraborate.  Nevertheless,
I see no problem with it working for Barry.  The pH would be ~8.6 if
"Borate" meant boric acid or ~9.3 if "Borate" meant sodium tetraborate. 
Barry's TBE is 0.133M Tris, 45mM boric acid (or 7.2mM sodium
tetraborate), 2.6mM EDTA.

"Classic" (classic means when I was first exposed to it) TBE has
equimolar amounts of Tris base and boric acid.  If memory serves, TBE is
89mM Tris, 89mM boric acid, 25mM disodium EDTA.  But that is a VERY old
recipe, my children.  At least 30 years old, when only proteins were
separated in electric fields.

Since then TBE has been modified.  BRL, e.g., has 10X TBE as 1M Tris
base, 0.9M boric acid, 10mM EDTA, and the Maniatis bible has TBE as 90mM
Tris, 90mM boric acid, 2mM EDTA.

Good luck,

Jim Owens



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