Message-Id: <9701301621.AA7972@pho903.sbphrd.com>
From: Jacek Mozdzanowski-1
Date: 30 Jan 97 8:20:54 EDT
Subject: HP-Seq Artifact Peak
To: Recipients of ABRF List <abrf@aecom.yu.edu>
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