A biopsy system comprises a control module, a localization assembly, a biopsy device, and a targeting cube. The biopsy device and/or other associated components are configured to selectively couple with a targeting cube that selectively couples with a grid plate having apertures for receiving the targeting cube. The targeting cube comprises a body defined by faces. The targeting cube further comprises guide holes that originate and terminate at the faces and pass through the body of the targeting cube to provide passageways through the targeting cube. To securely and removably fit the targeting cube within a grid plate aperture, the targeting cube also comprises a pair of gripping arms. The gripping arms extend from two opposing faces of the cube and snap fit around the walls of the grid plate to secure the targeting cube in position. The arms are resiliently biased to engage the grid plate.