Ethylammonium nitrate: a protein crystallization reagent

Ethylammonium nitrate (EAN) is a liquid organic salt that has many potentia l applications in protein chemistry. Because this solvent has hydrophobic a nd ionic character as well as the ability to hydrogen bond, it is especiall y well suited for broad use in protein crystallography. For example, EAN ma y be used as an additive, a detergent, a precipitating agent or to deliver ligands into protein crystals. A discussion of the crystallization of lysoz yme using EAN as a precipitating agent is given here.