I have two small points to add to what has been amply said already.
First, those columns (like the pre-filter 6000) are nice to use with
ion-exchange or metal affinity columns on FPLCs, attached right after a
superloop. Not gel filtration columns. Second, for small samples loaded
on gel filtration columns, a hard spin is advised; what I prefer is
actually using 0.5-ml spin cups (with 0.4 um filters) from Millipore.
There is practically no hold-up volume, and I have been lucky enough to
not lose protein over them yet.
http://www.emdmillipore.com/US/en/product/Ultrafree-MC-HV-Centrifugal-Filter,MM_NF-UFC30HVNB
Engin
On 9/17/14 3:10 PM, Karl-Magnus Larsson wrote:
Dear Anita,
As has been stated in another post I think, it is not a good idea to use a
guard column in front of a Superdex column or any gel filtration column. It
will dilute the sample and decrease the resolution and depending on the nature
of the aggregate and guard column it might just clog. If you have aggregates,
or suspect you have, installing an in-line filter will not help you in any
other way than protecting the column. You need to remove the aggregates by
ultracentrifugation beforehand and then make sure your sample volume is within
the recommended load volume for the column (read the documentation that comes
with column or get it from the GE Healthcare Lifesciences website) in order to
get the resolution you paid GE for.
If you do not have any inline filters and you have a bunch of users with varied
experience it might be a very good idea to install them and make sure that
people run proper methods where the column has been selected to get the right
max pressure settings. Compression of the matrix will also kill you column
pretty nicely.
Good Luck and Happy Hunting!!!!
KM
----- Original Message -----
From: "Anita P" <crystals...@gmail.com>
To: CCP4BB@JISCMAIL.AC.UK
Sent: Tuesday, September 16, 2014 1:29:44 AM
Subject: [ccp4bb] Guard columns from FPLC
Hi All,
Sorry for this off topic.
I have heard that there are these little columns called guard columns which
can be attached to AKTA purifiers. These columns prevent the incoming huge
aggregates to be deposited and blocking of the gel filtration columns.
Can any one advice me regarding where to purchase these columns. I could
not find them in GE website. We have Superdex 16/60 on AKTA purifier.
Thanks in advance.
Have a good day
Anita
--
Engin Özkan, Ph.D.
Assistant Professor
Dept of Biochemistry and Molecular Biology
University of Chicago
Phone: (773) 834-5498
http://ozkan.uchicago.edu
