🚀 go-pugleaf

A simple technique, which doesn't involve any macromolecular water trap is
use vacuum to concentrate your protein.  The aparatus is simple:  A side arm
flask, a one-hole rubber stopper which fits the top of the flask, and a
glass funnel.  
	1. Put the stem of the funnel through the hole in the stopper.
	2. Put your dialysis tubing over the end of the funnel stem, and
seal it.
	3. Hang the bag in the flask.  Determine what final volume you 
want to achieve, and fill the flask to a level so that with the bag hanging
in the flask, the voume of protein solution you want will be under the buffer.
	4. Put your protein in the bag using the funnel.  
	5. Apply vacuum to the side arm.
	6. Stir the buffer.
	
Using this technique, you can continue to add more protein solution through
the funnel, continue to remove excess salts by changing the buffer in the
flask, and never totally dry out the protein.

It works, but slowly.

Ellis Golub





In article <628brj$f79$1@agate.berkeley.edu>, lhom@nature.berkeley.edu (Louis Hom) writes:
|> I have a protein solution I need to concentrate and I'd like to use
|> dialysis tubing and dry PEG.  The only problem is, I don't have any PEG
|> with a MW higher than the cutoff for the dialysis tubing (12-14kD).  Can I
|> use polyvinyl alcohol instead (MW supposedly around 70kD)?  Thanks.
|> -- 
|> _______________________________________________________________________________
|> Lou Hom >K '93			   	  
|> lhom@nature.berkeley.edu 		    
|> http://www.ocf.berkeley.edu/~lhom	   

--
Ellis Golub                  Phone: (215) 898-4629
Biochemistry Department      FAX:   (215) 898-3695
University of Pennsylvania   ellis@biochem.dental.upenn.edu
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