In the micro-batch technique a whole array of oil mixtures can be tested to cover the wells. Different oils have different evaporation permeabilities,
and hence produce different rates of concentration changes of the protein/precipitant mixture under the oil.
Crystallization is a requisite step for obtaining structural information of macromolecules at near-atomic resolution. The methods described here
are therefore fundamental to studying enzyme mechanisms and protein-protein or protein-nucleic acids interactions, and are ultimately one of the
most important tools in structure-based drug design and development.