Affinity chtomatography - Sepharose vs Sephacryl?

I am wondering why, when it comes to activated supports, etc,
it is almost exclussively agarose/sepharose that is used.
Almost never sephacryl. Even though sephacryls should be
activatable by all the same chemistries available for agaroses...

Why? Can anyone think of a GOOD reason for that?

I would have thought that extremely high porosity of
Sepharcyls S500 and S1000, coupled with their high
rigidity and flow rates, will result in sorbents with
higher capacity and, perhaps, less non-specific binding.

Is this thinking wrong? If yes, why?

Thanks for any comments,

Dima

Hi Dima,

probably this is because most people (have to/want to) stick to
established and traditional methods. Those companies who offer the
corresponding kits don't need to change their ingredients as long as
the existing ones are selling well. Patent issues should be another
reason why not all possible combination researchers may think of are
available on the market. And in the time of 'publish or perish' none
of those who need to apply the methods dares to develop new ones. Also
because it becomes more and more difficult to combine the necessary
expertise for such developments in one research lab/setting due to its
commonly high specialization.

just some thoughts,

Wolfgang

BTW How do you limit shelf-live of your messages?

In article <[Only registered users see links. ]>, WS <[Only registered users see links. ]> wrote:

Well, I asked for a *good* reason :-) That's not quite it. Basically, I am
trying to understand why Pharmacia itself never sold any form of
activated or ligand-coupled Sephacryl and is selling a dozen of
various activated and affinity sorbents based on Sepharose.
OR:
If we are to spent some time and money optimizing a home-made
affinity matrix (all the way through - activation, linker, coupling), would
we be better off starting with Sephacryl or Sepharose?


I don't. Google does. I include the "X-No-Archive: Yes" header in
my messages. Just a matter of principle because I don't like databases
of any kind. In the old times, before Google started messing
up with Usenet, this was honored by DejaNews and subsequently
Google as a request of not showing up in their publically searchable
database. Now Google shows it for some time (no idea how long) but
then "deletes".

DK

Am 04.10.2008, 20:53 Uhr, schrieb DK <[Only registered users see links. ]>:


Part of the reason may be that the old Pharmacia company no longer exists,
it was bought first by Amersham and later by GE. It is quite possible that
the expertise in separation technology once concentrated at Pharmacia has
dispersed. The fact that the monographs on various separation techniques
that Pharmacia used to offer for free are no longer maintained or even
available (and it would be so cheap to put a pdf on their web-site)
strongly points in that direction, as does the fact that we no longer hear
about new techniques or matrices developed there. At least the Hoefer
electrophoresis line is now rescued. Sic transit gloria mundi :-(

On Oct 14, 3:48 pm, "Dr Engelbert Buxbaum"
<[Only registered users see links. ]> wrote:
....

I actually learned quite a bit from those booklets. Everything I
needed to know about gel filtration I learned from Pharmacia ;-)

Nick

--
Nick Theodorakis
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