Len,
I don't have hand-on experience and would also welcome comments of those
who do. However, in tring to decide whether to "upgrade" our existing HP
N-terminal sequencer, several questions have come up. Here are the two
which concern me the most:
1) With real-life samples, does the combined system lose sensitivity in
N-terminal sequencing compared to the straight N-terminal system?
I think there is reason to conclude that it does. If so, what are the
numbers?
2) Why is the included diode-array detector not supported properly?
As you know, the N/C system uses HP's new model 1100 HPLC, complete with
the 1100 model diode array detector. We've had a lot of experience with
the older HP detectors as well as this new one. The new one is clearly
superior in S/N and wavelength range.
Moreover, we use the older 1040 diode array on our N-terminal system rather
than the fixed wavelength detector, although that use is not supported by
HP. It's been very valuable for following multiple wavelengths when
peptides have been labelled with chromophores. Less often, we also capture
spectra during runs. Thus, I liked the idea that HP was going to put diode
array detectors on their sequencers.
But the N/C terminal software doesn't support management of multiple
wavelengths nor spectra acquired during runs. To me that's crazy, since
the software is based on HP's Chemstation which does support those
functions and much more. So, despite using the 1100 diode array detector,
the sequencer software has been crippled so that it effectively disables
the extra features of the detector.
I look forward to hearing from users as to whether these are real issues or
not.
Rod Levine
NIH
Bldg 3, Room 106 MSC 0320
Bethesda, MD 20892-0320
email: rlevine@nih.gov
voice: 1 (301) 496-2310
fax: 1 (301) 496-0599