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JOhn Smith intsales at neworkcity.com
Wed Oct 4 11:55:37 EST 2000


That's true

Trizma stands for a trade mark of Sigma tris. Actually, you should not adjust pH of running buffer, it is set itself  (8.3) if correctly prepared. Or, if you really want to adjust pH for some reasons, use say 3 M tris and noway NaOH. Also, one needs to be careful with a sample preparation. Say, when you precipitate proteins by TCA and/or collect HPLC fractions for further SDS-PAGE analysis - always add some tris to sample (drop or solid particle) until it turns blue again. If not, proteins may produce smeared spots after CBB staining.  

LD


David J. Meyer, Ph.D. <meyerdj at phibred.com> wrote in message news:ssvd831d0am68f at corp.supernews.com...
  As far as I know, "Trizma" is a Sigma trademark for their Tris. Trizma base (Tris base) of even "regular" Sigma grade will produce acceptable results, although the more pure grades may be desirable. The real problem comes if Tris (Trizma)-HCl is used, and NaOH or similar is used to adjust the pH; this has the effect of adding salt (and if a "recipe" is used without regard to molarity, will result in the wrong Tris concentration). For anything but the Tris-glycine-SDS tank buffer, Tris base and Tris-HCl can be mixed to produce the correct pH and concentration buffer (remember the Henderson-Hasselbalch equation?).
   
  Hope this helps.
   
  David J. Meyer, Ph.D.
  Pioneer Hi-Bred International, Inc.
    "Paul S. Brookes." wrote in message <4.3.1.2.20000925082212.00b29810 at norm.dpo.uab.edu>...
    Make sure your Tris is the correct grade.  It HAS to be Tris, electrophoresis grade.  I had this problem about a year ago and found it was because I used Trizma to make up solutions - apparently they are not the same thing!   The CSH mol-bio manual (book 3, section 18 I think) has a good explanation of this.   If you use the correct grades of Tris and Glycine, it should not be necessary to pH the solutions at all, they should automatically go to 8.3 if you add the correct amounts.


    Regards
    PSB

    _________________________________________
    Dr. Paul S. Brookes.            (brookes at uab.edu)
    UAB Department of Pathology,   G004 Volker Hall
    1670 University Blvd., Birmingham AL 35294 USA
    Tel (001) 205 934 1915     Fax (001) 205 934 1775
    http://peir.path.uab.edu/brookes

    The quality of e-mails can go down as well as up

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