Benzoylthiocholine Iodide is primarily used in biochemical research as a substrate for cholinesterase enzymes. It helps in studying the activity of these enzymes, which are crucial for nerve function. Researchers utilize it to measure cholinesterase activity in various biological samples, aiding in the diagnosis of conditions related to enzyme dysfunction. Additionally, it is employed in toxicology studies to assess the impact of inhibitors on cholinesterase activity, providing insights into the effects of certain toxins or drugs. Its application extends to the development of assays for detecting pesticides or nerve agents that inhibit cholinesterase enzymes.