A system and method for processing sample processing devices. The system can include a base plate adapted to rotate about a rotation axis. The system can further include a cover including a first projection, and a housing. A portion of the housing can be movable with respect to the base plate between an open position and a closed position, and can include a second projection. The first projection and the second projection can be adapted to be coupled together when the portion is in the open position and decoupled when the portion is in the closed position. The method can include coupling the cover to the portion of the housing, moving the portion of the housing from the open position to the closed position, and rotating the base plate about the rotation axis.