[Histonet] Tris buffer

[Min-Han Tan]

Sorry, a final comment - the recipe may not be ideal because the buffering
capacity of the TBST solution is quite low at this pH of 7.1. (i.e. the pH
can swing quite a lot)

The buffering capacity of a solution is usually best around pKa (in this
case 8.3) +- 1 i.e.  at a  final pH of between 7.3 - 9.3.

Regards,
Min-han


On Thu, Mar 6, 2008 at 9:08 PM, Min-Han Tan <minhan.tan <@t> gmail.com> wrote:

> Dear Margaret,
>
> Analyzing the recipe you have provided : you are preparing a solution of
> pH 7.1, Tris-HCl 50 mM, with NaCl concentration of 150 mM.
>
> This is based on the Henderson Hasselbach equation = 8.3 + log (1.4/121)/
> (6/157.6), where 8.3 is the pKa of Tris. The molarity of Tris is based on
> standard molecular weight calculations, Tris FW = 121 and Tris-HCl FW =
> 157.6.
>
> This seems like a reasonable recipe (NaCl = 150 mM - physiologic), except
> that perhaps I might aim for 7.4 or 7.2 from sheer familiarity. :)
>
> Regards,
>
> /min-han
>
>
> Min-Han Tan
> MBBS, MRCP(UK)
> Department of Medical Oncology
> National Cancer Centre Singapore
>
>
>
>
> On Wed, Mar 5, 2008 at 5:46 AM, Perry, Margaret <
> Margaret.Perry <@t> sdstate.edu> wrote:
>
> > We need to update our SOP's and I can't find a reference for our tris
> > buffer recipe.  I can find many recipes but not ours.  Our recipe is as
> > follows:
> >
> >
> >
> > 6 grams Trizma Hydrochloride
> >
> > 1.4 grams Trizma base
> >
> > 8.75 grams Sodium chloride
> >
> > Qs with water to 1 liter
> >
> >
> >
> > Do any of you have a reference for this recipe?
> >
> >
> >
> > Margaret Perry HT (ASCP)
> >
> > IHC Lab Manager Veterinary Science
> >
> > Animal Disease Research and Diagnostic Lab
> >
> > South Dakota State University
> >
> > Box 2175 North Campus Drive
> >
> > Brookings SD 57007
> >
> >
> >
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> >
>
>
>
> --
> /min-han




-- 
/min-han