Experiences with the venus heart method for determining acetylcholine.

Experiences with a little known method for determining acetylcholine in biological materials are reported. The test object is the isolated ventricle of the quahaug, Venus mercenaria, a preparation that is stable for many hours. Its minimal sensitivity for acetylcholine is between 0.005 and 0.01 µgm. %. The method is simple and highly specific, and the preparation may be used repeatedly, as often as every 5 to 10 min. Details of the method with illustrative results are given.