Abstract: A hand-held portable diagnostic assay system for conducting and recording luminescent reactions for generating and recording luminescent read-out signals generated by a testing assembly and recordable on an image recording medium. A carrier assembly receives the testing assembly and is operable between first and second conditions. An assembly prevents unintended insertion of the testing assembly into the carrier assembly when in the first condition, and a mechanism prevents unintended removal of the testing assembly from the carrier assembly when in the second condition.

Abstract: A wedge lock unit is disclosed for clamping a subsystem chassis with two outwardly extending spaced apart flanges to a system main frame, from which a single flange or tab extends outwardly. The wedge lock unit includes a stationary member which is fixedly attached to one of the flanges of the subsystem chassis. The stationary member has two opposite wedged or sloping sides along which two movable wedging members with mating sloping sides rest. A drive mechanism, in the form of a rotatable screw, is used to apply a force, resulting in a clamping force, which urges the movable wedging members toward the tab of the main frame, which is inserted between the wedge lock unit and the other flange of the subsystem chassis, until the tab becomes clamped between the movable wedging members of the wedge lock unit and the other flange of the subsystem chassis. Spring means are provided which produce a reaction force on the movable wedging members. The reaction force direction is opposite the clamping force direction.