Message-Id: <v03007800af02f9117d38@[128.231.233.117]>
Date: Wed, 15 Jan 1997 16:35:18 -0500
From: Mark Garfield <mgarfield@pop.niaid.nih.gov>
Subject: Radiosequencing
To: Recipients of ABRF List <abrf@aecom.yu.edu>
We have been attempting to do some radiosequencing on our ABI 477's.
The proteins of interest are dual labeled: 3H-leucine and 35S-methionine.
I have been using ATZ cycles (after replumbing line #22 from the B block to
line #11 on the A block), collecting the entire fraction, and counting it.
I also reset the instrument before starting the sequence, and activated
valve #22 to move the fraction collector to the correct position.
Our results have been dissapointing. The samples are hot enough, but
the peaks that I am getting are only 10 or 20 dpm's. In the past we have
successfully gotten good radiosequence results with our Beckman "spinning
cup" sequencer, but never have with the ABI instruments. I am confident
that the 477 sequencer is performing well with cold sequencing. Can
anyone offer any suggestions? I am not sure if the problem is sample
related, and will be trying to radiosequence a labeled standard.
Thank you in advance for your consideration of my problem.
Mark K. Garfield
Laboratory of Molecular Structure
NIAID/NIH
Rockville, MD
tel: 301-496-3786
email: MG102K@NIH.GOV