Affinity chromatography of proteins requires a ligand covalently bound to a solid support separated by a spacer of sufficient length. In the specific case of acetyl-cholinesterase we have reduced the conventional spacer synthesis from five to three steps. ... For affinity chromatography of cholinergic proteins the ideal ligand would be acetylcholine which, however, could not be used because it is easily hydrolyzed. We synthesized hydrolysis-resistent ligands. Different specific ...