A brief review of alternative electrofocusing techniques

Isoelectric focusing (IEF) is an excellent tool at analytical scales but has some drawbacks at preparative and process scales. Alternative electrofocusing methods have been around for over a decade but have only recently reached the point where they can begin to compete head-to-head with IEF. This paper describes some of the advances made in this field since the mid-1980s and shows how they are related to IEF by a common mathematical expression. In addition, one new technique is described which allows real-time computer-control of the focusing gradient.