PharmPK Discussion - Tris vs Phosphate for microsomal incubations

PharmPK Discussion List Archive Index page

On 22 Oct 2002 at 09:45:25, "Prabhu, Saileta" (sprabhu.aaa.sunesis.com) sent the message


Dear All,

Is there a significant difference between using Tris and Phosphate
(both at 0.1M concentration and pH 7.4) in microsomal incubations?  The
only reason I prefer to use Tris in the incubations is because my
analysis is by LC/MS (electrospray) and we analyze about 200-400
samples per day. I think using phosphate would not be good for the ion
source.

-Saileta

Back to the Top

On 22 Oct 2002 at 12:59:45, NTeuscher.-at-.npsp.com sent the message


Regardless of which is better for microsomal incubations, you can use a
diverter valve on your LC/MS to divert the phosphate salts away from
the MS detector and only analyze the compounds of interest. This saves
the ion source and allows you to use phosphate buffers for your assays.

Nathan

Nathan S. Teuscher, PhD.
Drug Metabolism Scientist
NPS Pharmaceuticals
420 Chipeta Way
Salt Lake City, UT 84108
Email: nteuscher.-a-.npsp.com

Back to the Top

On 22 Oct 2002 at 17:55:03, sunil bajad (sbajad.aaa.yahoo.com) sent the message


Dear Saileta,

1) phosphate buffer tend to precipitate polyvalent
cations (Mg++, Ca++,Fe+++). Phosphate is known to
inhibit kinases,dehydrogenases etc.

2)Tris can form Schiff bases with aldehyde and
ketones.

Dr. Sunil bajad (Patil)
Research Associate
Department of Medical Sciences
School of Vet. Medicine
University of Wisconsin-Madison,
2015 Linden Drive west,
Madison 53706, WI,USA

Back to the Top

Want to post a follow-up message on this topic? If this link does not work with your browser send a follow-up message to PharmPK@boomer.org with "Tris vs Phosphate for microsomal incubations" as the subject

PharmPK Discussion List Archive Index page