The present disclosure relates to an add-on cap for electroporation of tissue comprising: 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 adapted to be sealingly engaged to a tip of an instrument, such as an endoscope. The disclosure further relates to a system for electroporation of tissue comprising the add-on cap and an endoscope. The disclosure also relates to a method for electroporation of tissue using the cap mounted on the tip of the endoscope, comprising the steps of: positioning the distal open end of the add-on cap adjacent to tissue to be treated with electroporation, wherein the positioning is visually assisted by imaging through the add-on cap from the distal open end to the proximal open end applying vacuum in the internal volume through the proximal open end of the add-on cap, thereby aspirating tissue into the internal volume and electroporating the aspirated tissue by applying an electric field between the electrodes of the add-on cap.La présente invention décrit un capuchon complémentaire destiné à lélectroporation de tissu comprenant : au moins une paroi latérale fermée, telle quune paroi latérale cylindrique une extrémité ouverte proximale une extrémité ouverte distale la au moins une paroi latérale fermée et les extrémités ouvertes proximale et distale définissant un corps creux présentant un volume interne deux électrodes sur les côtés opposés du volume interne, les électrodes configurées pour appliquer un champ électrique destiné à lélectroporation du tissu à lintérieur du volume interne, où lextrémité ouverte proximale est adaptée pour être engagée de manière hermétique au
