Affinity purification of a liver protein

[Mike Green]

Hello,
	We are preparing to isolate a cytosolic liver protein using affinity
chromatography.  We are not sure what the degree of expression will be,
however it should be high.  My question is should any preliminary
"clean-up" be performed on the cytosols prior to affinity purification. 
Perhaps a size exclusion or ion-exchange column?  Are there any
standardized protocols for liver tissues?

Thanks,
Mike Green