mercaptoethanol

noun
mer·​cap·​to·​eth·​a·​nol | \ mər-ˌkap-tō-ˈeth-ə-ˌnȯl How to pronounce mercaptoethanol (audio) \

Medical Definition of mercaptoethanol

: a reducing agent C2H6OS used to break disulfide bonds in proteins (as for the destruction of their physiological activity)