A robotic device for loading and moving covers that may be used in a process for extracting molecules, in particular DNA, comprising: - a head moving in a three-dimensional space with respect to a support surface of the device under the thrust of actuators controlled by an electronic unit; - a gripping and transport structure carried by the head adapted to pick up/use/unload a plurality of disposable covers, each comprising a tubular element (10-t) closed at a first end (10-a) and defining at a second end (10-b) thereof a circular opening surrounded by a cylindrical annular edge (10-r), whereby the gripping and transport structure comprises a first upper structure directly carried by the head and a second lower structure movable with respect to the first upper structure along a vertical guide interposed between the first structure and the second structure (9a, 9b) between a first travel end position in which the first structure is next to the second structure and a second travel end position in which the lower structure is spaced apart from the upper structure by a predetermined distance D; - a plurality of elongated elements carried by the upper structure arranged with first axes parallel and coplanar to one another so as to form an array of elongated elements spaced apart from one another by a center-to-center distance KK; each elongated element carrying a respective magnetic element at a free end thereof; - a plurality of connecting walls carried by the lower structure and each adapted to be coupled to a respective tubular element (10-t); characterized in that the robotic device further comprises: - quick coupling/release means interposed between the first upper structure and the second lower structure; said robotic device being adapted to carry out a first step of positioning said head with respect to said covers such that the first and second structures are approaching each other up to closing the quick coupling/release means and such that the coupling of the second end portion of each tubular element (10-t) to a respective connecting wall and the inlet of each elongated element within a respective cover is obtained. - a head moving in a three-dimensional space with respect to a support surface of the device under the thrust of actuators controlled by an electronic unit; - a gripping and transport structure carried by the head adapted to pick up/use/unload a plurality of disposable covers, each comprising a tubular element (10-t) closed at a first end (10-a) and defining at a second end (10-b) thereof a circular opening surrounded by a cylindrical annular edge (10-r), whereby the gripping and transport structure comprises a first upper structure directly carried by the head and a second lower structure movable with respect to the first upper structure along a vertical guide interposed between the first structure and the second structure (9a, 9b) between a first travel end position in which the first structure is next to the second structure and a second travel end position in which the lower structure is spaced apart from the upper structure by a predetermined distance D; - a plurality of elongated elements carried by the upper structure arranged with first axes parallel and coplanar to one another so as to form an array of elongated elements spaced apart from one another by a center-to-center distance KK; each elongated element carrying a respective magnetic element at a free end thereof; - a plurality of connecting walls carried by the lower structure and each adapted to be coupled to a respective tubular element (10-t); - quick coupling/release means interposed between the first upper structure and the second lower structure;