Hello.
Sounds like you have a bad batch of columns. Have you considered
trying the PTH column from Beckman-Coulter? It would be interesting
to see the results. I deal with a very simple recipe for Buffer A.
My present Beckman supplied column is over a year old now.
Also, HP sold a robust PTH amino acid column which is probably still
available. Good luck. Regards, Tom (still a die-hard Porton user) Miller
Thomas J. Miller
Dupont Company
Protein Sequencing Lab
302-695-1745
Opinions are my own and not of my employer.
Also, not associated with Beckman or HP.
you 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
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