Re: Source for Poros tip columns

GARY.W.LANGE@monsanto.com
14 Dec 1998 13:44:02 -0600

Donald Sheer's Zip tips have finally made it to market. They are
available thru Millipore (1800-645-5476) 8 pack ZTC 18S008, 24 pack
ZTC 18S024 ($55), 96 pack ZTC 18S096 ($170),& 10 x 96 pack ZTC 18S960.
At the March 98 ABRF Don presented some info on desalting a 31 mer
oligo along with a lot of info on desalting tryptic type peptides.
Most of my work with these has involved using them to concentrate and
desalt tryptic fragments & following with MALDI. They work extremely
well for this purpose. Instructions are also at the Millipore
website. One thing to remember :-) don't forget to acidify your
mixture before trying to bind it to the tips. I have also found that
it takes a bit more acetonitrile to elute peptides from this Poros
media than from something say like a Vydac C-18 resin. I have been
pushing 80-90% Acetonitrile .1% TFA for elution. I think that once
people start using these tips they will find a lot of other useful
ways to use them. I would think that they would be great for chemical
modification/cleanup experiments for peptides. With a little work
maybe one could even figure out how to elute the tip directly into an
electrospray MS.

Although they have been used to desalt myoglobin I haven't been very
successful with the proteins that I've attempted. (They are much more
hydrophobic than myoglobin). It seems like the protein never gets
eluted off of the resin. It would be great if Millipore followed up
with a C-4 version of this tip too.

I could also see a use for a "microenzyme column" if the ziptips were
available in some sort of activated form so that you could easily add
the enzyme of choice. Something with a leash, (like Bio-Rad's
affi-gel 10 with it's 10 atom spacer arm), but with Poros type bead.
The Activated Poros beads, in their current configuration(s) are too
difficult to readily attach scarce/expensive enzymes without a lot of
trial & error & enzyme waste. A 1-2 step hydroxysuccinimide
activation linkage would be perfect. Any suggestions?

Gary Lange
gary.w.lange@monsanto.com
Monsanto Co.


______________________________ Reply Separator
_________________________________
Subject: Source for Poros tip columns
Author: abrf-request@aecom.yu.edu at INTERNET
Date: 12/11/1998 10:31 PM


Hello:

We are looking for a source for "Poros gel-loading tip columns". These
are used for desalting samples (esp. DNA) prior to MS on a MALDI-TOF
machine.

Any help would be greatly appreciated.

Jack

_____________________________________________________ Jack Presley
voice: (530) 752-7327
Protein Structure Lab fax: (530) 752-8969 UC Davis
http://psl.ucdavis.edu