From: StvTindall@aol.com
Date: Thu, 30 Jan 1997 11:11:05 -0500 (EST)
Subject: Re: HP-Seq Artifact Peak
To: Recipients of ABRF List <abrf@aecom.yu.edu>
On 97-01-30, Jacek Mozdzanowski wrote:
"What you see is (most likely) alanine..."
----------------------------------------
Jacek,
Don't you mean aniline? If yes, aniline is not our current problem. We
see aniline between Asn and Ser, not between Thr and Gly. Of late, our
aniline problems have been associated with damaged autoinjector rotor seals.
The rotor seal was just replaced.
You are absolutely right about the initial 3.5 flask drying time being
too short (we have been using 180 sec since August 96). Actually, each
current HP method (3.1, 3.5 and 3.1 PVDF) needs a different initial flask dry
time. The acid addition is also a bit excessive.
Steve
====================
Stephen Tindall
Argo BioAnalytica, Inc.
Phone: 1-201-605-2100
Fax: 1-201-605-2104
StvTindall@aol.com
====================
Subj: HP-Seq Artifact Peak
Date: 97-01-30 09:00:06 EST
From: Jacek_Mozdzanowski-1@SBPHRD.com (Jacek Mozdzanowski-1)
Sender: abrf-request@aecom.yu.edu (Association of Biomolecular Resource
Facilities)
To: abrf@aecom.yu.edu (Recipients of ABRF List)
Steve,
What you see is (most likely) alanine. The main reason is insufficient
drying
time at the first step of CNV cycle (preset by HP at 100 sec for the 3.5
chemistry). 3.5 chemistry uses different solvents and it usually takes a
little bit longer to evaporate the solvent properly. 10-20 ul residual
volume
recommended by HP seems to be insufficient - I let it evaporate almost to
drynes (almost is a key word here). Adjust the drying time, run a sequence
about 20 cycles long and look for improvement. If this does not help then
replace the conversion flask and check if all the deliveries comply with the
HP
recommendations. Watching the cartridge and the conversion flask during 2 or
3
cycles is not my favorite, but most of the time it helps to solve problems.
Jacek Mozdzanowski
Analytical Sciences
SmithKline Beecham