Fractionation by charge — Chromatographic methods also can fractionate specifically or generally. Aurum ion exchange (AEX and CEX) mini columns allow selective purification of either acidic or basic proteins. Easy-to-use Aurum ion exchange kits selectively enrich either acidic or basic proteins and can be used with a variety of starting samples.
| Total protein sample | AEX-bound sample | CEX-bound sample |
 |  |  |
Fractionation of rat brain tissue using Aurum ion exchange mini columns. Rat brain total protein extracts (3 ml) were loaded onto an Aurum AEX or CEX mini column, then eluted using the recommended protocol. The fractionated samples were treated with the ReadyPrep reduction/alkylation and 2-D cleanup kits prior to 2-D gel analysis. Left, total rat brain protein; center, sample that bound to the Aurum AEX column (acidic proteins); right, sample that bound to the Aurum CEX column (basic proteins).
