Hi Judy,
A couple of questions as we use the same system/reagents etc. without the
problems that you report and have recently installed a new column without
incident. 1) Are the 2 new columns from the same lot and if so, what is
the lot #? 2) Have you tried to reset the gradient conditions to the
programmed standard (including column temperature)? Is it possible that
you needed to modify your gradient over time to accommodate your old column
and those current conditions, while favorable for the old column, are not
appropriate for a new column? (sorry, I know Barbara or Bob have probably
already asked you these same questions.)
David
At 09:59 AM 1/4/01 -0500, phelp001@mc.duke.edu wrote:
>Hello
>I am having a lot of difficulty with the Brownlee Spheri-5 PTH, 5 u,
>220x2.1 mm
>columns that we purchase from ABI for the protein sequencer.
>
>The front half of the chromatogram is OK (separation and such) but the DTT is
>high. The back half, Pro and further, is not good. The peaks are too small.
>Proline is very large and tech support thinks that DPU is coming out too early
>and coeluting with Pro. The PMTC peaks are also way small.
>I am running Buffers A3 and B2. All reagents are fresh. New standards were
>prepared
>I tried putting back on my old column and these problems went away.
>Unfortunately the column is too old to use now.
>I have tried two new columns from ABI with the same result.
>
>Any clues?
>
>Thanks
>
>Judy Phelps
>phelp001@mc.duke.edu
David C. Chiara, M.D., Ph.D.
Research Associate
Department of Neurobiology
Harvard Medical School
220 Longwood Avenue
Boston, Ma. 02115
ph: (617) 432-1729
fax: (617) 734-7557
Email: David_Chiara@hms.harvard.edu
www.hms.harvard.edu/bss/neuro/cohen/
This archive was generated by hypermail 2b29 : Fri Jan 05 2001 - 08:42:46 EST