a few questions about ion exchange chromatography - (Nov/02/2011 )

if i use affinity purification, after this step, i must reduce the salt and buffer concentration when i want to make ion exchange.
Should I use desalting columns for this?
Maybe, after affinity, gel filtration is enough.
I will post my results whenever I get.

you can use desalting (gel filtration) columns or you can dialyze.

be careful, with reduced ionic strength there is more chance of non-specific binding to the matrix.