Hello all;
Have any of you protein sequencing people been having trouble with short
lifetimes on ABI PTH columns? Over the years I have expected these columns
to last 3-4 months with careful use, but lately this has not been the case.
I treat them very gently, break them in properly and run the older slower
gradient to keep operating pressures low. I use ABI solvents and reagents.
Under the assumption that there is something wrong with my instrument
(ABI473) maybe leaking something nasty and poisoning the column, I have
replaced the conversion flask and the only valve block I could find with a
leak, block 1. Hasn't made a bit of difference. The symptoms are that my
hydrophobic residues are disappearing. Weird, I know. I will see data
something like this....
1. asp 8 picomoles
2. thr 5 "
3. pro 9 "
4. val 0 "
5. ser 3 "
6. asn 8 "
7. leu 0.2 "
8. tyr 1 "
When I say "0" for valine, I really mean "0"...not even a whisper. It's
obviously being coupled and cleaved OK, but where did it go? Today I've
installed yet another new column and will get beautiful data for about 3
weeks, then it will start to deteriorate again. Any hints much appreciated.
Best regards,
Sandy Kielland
Victoria Protein Microchemistry Centre
Department of Biochemistry and Microbiology
University of Victoria
Victoria B.C. CANADA
phone: (250) 7218884
FAX (250) 7218855
Email Kielland@UVic.ca
Webpage http://www.proteincentre.com
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