dialysis

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cellzlife
cellzlife's picture
dialysis

hi ....
can anyone please tell me how to carry out dialysis using sephadex for concentration of protein.... i have a very little amount of protein solution with me ( around 2ml)
 

kjosephs
kjosephs's picture
I have never concentrated

I have never concentrated proteins by dialysis against polyethylene glycol (PEG) or sephadex out of concern that they will introduce small molecule impurities into my sample.  I have always used disposable spin concentrators like amicon ultra 4's that allow for the rapid concentration of protein solutions up to 4 mL down to as little as 50 uL. 
http://www.millipore.com/catalogue/module.do?id=c7719
For concentration of a 2 mL sample by dialysis I would use a slydalyzer casette.  Here is a method for using a slidalyzer for concentration by dialysis against Pierce's "Concentrating Solution" which is probably ultrapure peg 20,000 or something similar.  I imagine you could just easily use sephadex since that is what you were asking about. 
http://www.piercenet.com/files/0631as4.pdf
Also, here is a thread from Scientist Solutions that may be of some help.  Perhaps some of these members will also have some advice?
http://www.scientistsolutions.com/t4109-i+need+help+concentrating+a+protein+isolate.html
 
Good luck!
 
 
 

Jason King
Jason King's picture
For small volumes I would use

For small volumes I would use the Slide-A-Lyzer products available through Thermo Scientific:

 
http://www.piercenet.com/Products/Browse.cfm?fldID=04010160
 
I have used the dialysis cassettes for volumes of 1-3mL, but I see from their site that they have some new MINI units for really small volumes.