Date: Mon, 12 Apr 1999 10:06:16 -0400
From: Jane Nagel <jnagel@genetics.com>
To: Recipients of ABRF List <abrf@aecom.yu.edu>
Subject: Pioneer MPS
Hello all,
I am new to the Pioneer MPS system and am having a couple of recurring
problems
which are eluding solution. When we run the MPS option, we have poor
sysnthesis results (things that synthesize like a charm on the old ABI
430),
and we consistantly see a +14 mass. Perceptive is unable to find an
answer for
us so I thought perhaps someone here has some ideas. We are running
extended
cycles, Fmoc chemistry with HATU/DIEA activators.
Thanks in advance,
Jane Nagel
Genetics Institute
Cambridge MA
Dear Jane
Your plus 14 is probably a methyl ester formed from the final methanol
wash. I recommend you leave out the methanol wash at the end of the
synthesis. I never use it for this reason. I am just about to take
delivery of the MPS system for our Pioneer so I will be able to share
your experiences with the system !!
Dr Graham Bloomberg
Dept Biochemistry
Medical School
University of Bristol
BRISTOL BS8 1TD
UK