Abstract: A pipette tip rack system is disclosed that includes a plurality of tip racks that may be nested one upon the other with an integrally formed locking mechanism that locks each rack to the one immediately below it. A cover member is also included that acts as a cover for the top rack in the stack. This cover also utilizes the same locking mechanism. Also included is a bottom member that serves as a dust cover and uses the same locking mechanism to permit its fixture to the bottom rack. The whole system when lockingly fixed together forms a relatively secure unit so that if it is upset the tips will not spill out. Further, each element in the stack retains its sterile condition. Finally, the stack of racks may be combined with a box having a top that fits over the cover and a bottom that receives the bottom member and lowest rack. This box may be removed from the stack and assembled so that a single rack may be used remote of the stack.