The Assay of Acetylcholine on the Superfused Frog Rectus Muscle

Abstract
A method of superfusion for assaying acetylcholine on the eserinised frog rectus muscle applying each dose in a volume of 0·2 ml. is described. The sensitivity of the superfused preparation is compared with that of the preparation in a 5 ml. bath and is 10 to 20 times more sensitive than the bath preparation. Results of 10 parallel assays (2 + 2) suggest that the method of superfusion gives a reliable and accurate assay of acetylcholine.