The apparatus is a mechanism for acquiring, holding, and enabling the movement of a cassette-shaped article, such as a reagent or sample cassette, which may be part of an automated diagnostic analyzer, such that the apparatus can tolerate a significant degree of cassette misplacement and/or misalignment during the acquisition maneuver. The mechanism furthermore enables simultaneous two-dimensional movement of the acquiring gripper jaws such that the inter-jaw distance decreases at the same time as movement in an upward vertical direction is provided while the jaw movement is adequately smooth so as not to disturb the physical state of the sample.