Concentration from GuHCl ?

Dr. Barry Phipps phi at
Mon Feb 7 08:23:39 EST 1994

Hi Roger,

I used to work with protein samples (column fractions, etc.) in the presence
of 6M guan-HCl and I'm pretty sure they can be concentrated with either
acetone precipitation (5 vols -20C acetone, sit 20 min at -20C, sediment
15000 x g at 4C, wash pellet with ether at 0C) or TCA precipitation (equal
vol 0C 20% trichloroacetic acid, sit 15 min at 0C, sediment 15000 x g at 4C,
wash pellet with cold acetone) or both.  The thing to do is first try this
with 6M guan-HCl in buffer (no protein).  I'm pretty sure the TCA procedure
will work.  Wash pellet well to get rid of residual guan-HCl which will screw
up your gel lanes.  Another idea is to use a Centricon for rapid concenration
of small volumes, diluting a couple of times with buffer to get the guan-HCl
concentration down below 50 mM or so.  Good luck.

Barry Phipps

Barry M. Phipps
Macromolecular Structure Group
Biotechnology Research Institute
c/o Institute for Biological Sciences
National Research Council
Building M-54, Montreal Road
Ottawa, Ontario
E-mail:  phi at  (
Phone: (613) 990-0889  Fax: (613) 941-4475

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