Abstract: An add-on cap for electroporation of tissue including: at least one closed sidewall, such as a cylindrical sidewall; a proximal open end; a distal open end; the at least one closed sidewall and the proximal and distal open ends defining a hollow body having an internal volume; two electrodes on opposite sides of the internal volume, the electrodes configured to apply an electric field for electroporation of tissue inside the internal volume, wherein the proximal open end is sealingly engaged to a tip of an instrument, such as an endoscope. A system for electroporation of tissue including the add-on cap and an endoscope.