Affinity enrichment vs affinity purification

What a great couple of papers out of Max Planck this week!

In yet another incredible paper in press at MCP, Dr. Mann's lab explores the difference between affinity purification and affinity enrichment experiments and how we should maybe take a step back and evaluate how we've been doing things.

Here is the distinction:
Affinity purification -- you look for a specific interactor(s) of your protein of interest.  You do multistage separations to get it super clean.  Protein presence vs. protein non-presence in your control says its an interactor.  Spend tons of time perfecting your sample prep.

Affinity enrichment -- you look for protein-protein interactions in a single-stage kind of way.  Pull down your protein of interest and its interactors.  Up-regulation of proteins in your pull down vs your control suggests that it is an interactor. (I'll add these to the translator).

End result?  Enrichment is just as good AND WAY EASIER from a sample prep view point.  The argument they make? We can do a pretty good job of getting a whole proteome in one shot, of course we can do protein-protein interactions this way.

The whole thing was validated by pulling down yeast proteins and by scoring the number of known interactors that popped up.

You can find this paper (still in press and open access) here!