Affinity electrophoresis is based on the reaction between interacting components during electro phoresis. In this review is given the general analytical technology. The main advantages of the analytical electrophoresis approach appear to be: 1. It can separate macromolecules that interact with a specific ligand from those that do not. 2. It can be used for studies of interacting macromolecules. 3. It is not necessary to purify interacting components. 4. A multitude of proteins reacting with the same ligand may be studied simultaneously. 5. It can be generalized to interactions other than those between lectins and glycoproteins.