> Dear All
>
> I am very disappointed, and had heard from another source that HP will not
> be marketing an Edman sequencer.
> The most annoying fact of this is that, not that ABI is not good, ABI has
> not (possibly never) taken the initiative in innovation. Porton pushed
them
> with multiple cartridges, HP pushed them with sensitivity, to identify a
few
> key upgrades over the 470A.
>
> alex
>
> Alexander W. Bell
> fax (514) 398-5047
> email ehjb@musica.mcgill.ca
> McGill University
> 3640 University St.
> Montreal Quebec
> H3A 2B2
> ----- Original Message -----
> From: <StvTindall@aol.com>
> To: Recipients of ABRF List <abrf@aecom.yu.edu>
> Sent: Thursday, April 29, 1999 1:50 PM
> Subject: Re: HP Seq: Lys Recovery Problem (PDF Figs. Attached)
>
>
> > Jim,
> >
> > Your comments about the 494s being more sensitive and having better
> IYs
> > than HPs struck a nerve. I hear this comment a lot and I think the
> > implications are bogus. If you (meaning everyone) look at the big
picture,
> > the HP can perform equal to or better than the 494 and here's why:
> >
> > 1) By the time you get in 10-15 residues, the higher HP RY compensates
for
> > any difference in IY. Residues beyond that are just icing on the cake.
> >
> > 2) Proper maintenance of the HP in combination with continuous running
(or
> > "slow running/idling") is essential to keeping the HP at peak
performance.
> > An HP that has not been used for a week takes at least 3 weeks of
> continuous
> > running to get it back on top of its game. Been there, done that.
Our's
> > never stop.
> >
> > 3) The biggest problem with the HP has been its detector system, which
is
> > where the boost in sensitivity for the "241" came from, not from any
> changes
> > in the sequencer proper. Of course, if you installed the C-terminal
> > reagents, most of the benefits went away. We installed HP 1100 VWD
> detectors
> > plus semi-micro flow cells on both G1005A systems for about $6.5K per
> system
> > and saw an immediate boost in sensitivity. We now do routine peptide
> > identification analyses starting with 200 fmol IYs and still get the
high
> RYs
> > at that level. The higher RY even allows the HP to give a cLC a run for
> its
> > money at this level for a lot less operating expense.
> >
> > 4) The HP Edman chemistry and HPLC methods are surprisingly robust and
> rarely
> > fail to produce usable data, even from nearly garbage samples.
> >
> > The average 494 user who only runs occasionally probably does get
> better
> > overall performance than the average HP user who only runs occasionally,
> but
> > a properly maintained and continually run HP using an HP 1100 VWD
detector
> > (not an HP 1100 DAD) can outperform a properly maintained and
continually
> run
> > 494. Of course, it helps if the reagents work properly.
> >
> > All of this may be moot, however, since HP appears to have stopped
> > actively marketing its sequencer some time ago.
> >
> > I get so tired of hearing HP users say "I can't get under 2 pmol".
> If
> > you can't get under 2 pmol, then you are doing something wrong, plain
and
> > simple. Maybe it's just easier to complain about performance than to do
> > something about it. Based on the limited HP-user responses to my
> questions,
> > one gets the idea that most HP users don't seem to care about
performance
> > issues. The crop you harvest has a lot to do with the seeds you
planted.
> >
> > Steve
> > ====================
> > Stephen Tindall
> > Argo BioAnalytica, Inc.
> > ====================
> >
> > Subj: Re: HP Seq: Lys Recovery Problem (PDF Figs. Attached)
> > Date: 4/28/99 1:24:16 AM Eastern Daylight Time
> > From: jmackint@proteome.org.au (jim mackintosh)
> > Sender: abrf-request@aecom.yu.edu (Association of Biomolecular Resource
> > Facilities)
> > Reply-to: jmackint@proteome.org.au
> > To: abrf@aecom.yu.edu (Recipients of ABRF List)
> >
> > Steven,
> >
> > Just some quick thoughts slightly off-topic. For our in-house work I
have
> > found Mallingkrodt HPLC grade acetonitrile (HPs L1) and methanol (HPs
L2)
> > work fine in the G1005As, no problems. At around AUS $60 for 4 litres
> it's a
> > huge saving. Also for our in-house work I have found that used PVDF
> sample
> > columns can be re-used with no problems. You simply re-prep them using
> the
> > PVDF 3.1 prep program and all pre-existing protein is removed. I'm yet
to
> > attempt re-using the 3.1 protein columns but I expect this can also be
> done.
> > I'll be interested to hear how you go with your specific
> > problem. It may be the R2.
> >
> > As I have said before I have a tremendous amount of respect for the HP
> > sequencers. My analogy is the HPs are like Harley Davidson's whereas
the
> > ABIs are like Hondas. The 494s are more sensitive (they have an
excellent
> > initial yield) and are quicker, but if you want a simple machine to mosy
> on
> > down the highway in comfort take the Harley.
> >
> > Jim Mackintosh
> > Australian Proteome Analysis Facility, Level 4, Building F7B, Macquarie
> > University, Sydney, NSW, 2109, Australia
> > Tel: + 612 9850 6364 Fax: + 612 9850 6200 E-mail:
jmackint@proteome.org.au
> > http://www.proteome.org.au/
> >
>