One thing you can do, if your chromatography will tolerate it, is dilute
your sample and use a larger loop--the larger the loop in a way the less
sample you use--a 20ul loop uses 80 ul on this formula, 4 times the
sample; a 50 ul loop uses 125 ul; and a 100ul loop uses 200 ul, 2 times
the sample.
Hope this is helpful,
Deb McMillen
Institute of Molecular Biology
University of Oregon
Eugene OR 97403
On Wed, 9 Jun 1999, Freedy, James [OBI] wrote:
> Greetings,
>
> I am involved in amino acid analysis of a particular glyco-protein,
> for release testing. My efforts are in support of a validated method.
> Currently our QC lab is and has been release testing based on the P/E-ABI,
> PTC, derivitization and subsequent separation on c-18 R/P chromatography
> system. As I perceive the story, this instrumentation is no longer being
> supported and what little support there is, now, will eventually disappear
> all together.
> So to make a long story short, we now have in our laboratory, a
> system which has Beckman's name on it, to be exact; 126AA solvent module,
> 166 detector, 232 post column reactor, 507 system gold autosampler and a 350
> IBM Personal computer. I have been validating this system and find that it
> works acceptably well, but the autosampler is something from a different
> realm. I understand that Beckman makes a 508 autosampler which does not have
> a column oven incorporated into it's design. Any experience with this
> situation would be appreciated. Should I up-grade to the 508 and buy a
> column oven, which by the way would have to be programmable to accommodate
> the chromatography or should I struggle along with the current autosampler
> which uses three times the actual amount of sample needed for injection.
> Another option would be to switch the whole post column ninhydrin system
> over to an HP1100 or a Waters Alliance system any and all constructive
> comments would be appreciated.
>
> James G. Freedy
> Ortho Biotech
> Raritan, N.J.
>
>
>