6-(TRIETHYLAMMONIUM)HEXYL METHANETHIOSULFONATE BROMIDE is a water soluble, bulkier analogue of the charged MTS reagent MTSET. 6-(TRIETHYLAMMONIUM)HEXYL METHANETHIOSULFONATE BROMIDE have been used successfully with SCAM (substituted cysteine accessibility method) to probe the topology and fu nction of a number of ligand-gated ion channels and transporter proteins.