Abstract: An improved apparatus for effectively disrupting biological samples contained in cuvettes to which beads have been added. In the apparatus, a special arm/bearing subassembly is driven and oscillated by a motor in a manner to attain cellular disruption of the biological samples without degradation of their cellular components. In the preferred form, the special arm/bearing subassembly has a cam, bearings, and a bearing sleeve which cooperate with a motor drive shaft to rotate a yoke with two arms holding four cuvettes. For increased safety and environmental protection, special sample retainers can be provided to better secure the cuvettes and the arm/bearing subassembly is enclosed in a sample chamber which provides a secondary containment compartment that contain any spillage.