A system for processing sample processing devices, the system comprising: a base plate operatively coupled to a drive system and having a first surface, wherein the drive system rotates the base plate about a rotation axis, and wherein the rotation axis defines a z-axis; a cover adapted to be positioned facing the first surface of the base plate, the cover including a first projection; a housing comprising a portion movable with respect to the base plate between an open position in which the cover is not coupled to the base plate and a closed position in which the cover is coupled to the base plate, the portion including a second projection, the first projection and the second projection adapted to be coupled together when the portion is in the open position and decoupled from each other when the portion is in the closed position, such that the cover is decoupled from the portion of the housing and rotatable with the base plate about the rotation axis when the portion is in the closed position and when the cover is coupled to the base plate; a sample processing device comprising at least one process chamber (152, 154) and adapted to be positioned between the base plate and the cover, the sample processing device rotatable with the base plate about the rotation axis when the sample processing device is coupled to the base plate; characterized in that the system further comprises: at least one first magnetic element operatively coupled to the base plate; and at least one second magnetic element operatively coupled to the cover, the at least one first magnetic element configured to attract the at least one second magnetic element to force the cover in a first direction along the z-axis. a base plate operatively coupled to a drive system and having a first surface, wherein the drive system rotates the base plate about a rotation axis, and wherein the rotation axis defines a z-axis; a cover adapted to be positioned facing the first surface of the base plate, the cover including a first projection; a housing comprising a portion movable with respect to the base plate between an open position in which the cover is not coupled to the base plate and a closed position in which the cover is coupled to the base plate, the portion including a second projection, the first projection and the second projection adapted to be coupled together when the portion is in the open position and decoupled from each other when the portion is in the closed position, such that the cover is decoupled from the portion of the housing and rotatable with the base plate about the rotation axis when the portion is in the closed position and when the cover is coupled to the base plate; a sample processing device comprising at least one process chamber (152, 154) and adapted to be positioned between the base plate and the cover, the sample processing device rotatable with the base plate about the rotation axis when the sample processing device is coupled to the base plate; at least one first magnetic element operatively coupled to the base plate; and at least one second magnetic element operatively coupled to the cover, the at least one first magnetic element configured to attract the at least one second magnetic element to force the cover in a first direction along the z-axis.