1. After a brief survey of the basic affinity electrophoresis concepts, the usual ways for preparing affinity electrophoresis ligands are examined. 2. Then results obtained on cholinesterases are reviewed. This section includes (a) structural and functional investigations on anionic sites, i.e., study of ligand-induced conformational change, organophosphate-induced "aging," genetic variants, and active-site topology; and (b) characterization of cholinesterase conjugates (hybrid proteins) and glycoinositol phospholipid-anchored cholinesterases. 3. The future prospects of affinity electrophoresis, e.g., investigations on the esteratic site and exploration of the carbohydrate moiety, are emphasized in the concluding section.