Stack Racks provide a cost-effective and environment-conscious alternative to racked tips. Stackable racks of tips in the 8x12 (96 tips) or 8x24 (192 tips) configuration utilize the same bottom and lift-off lid, minimizing unnecessary plastic. Lid and bottom are hinged for use as a storage box when empty, or may be reused with Stack Rack refills. Storage box can be autoclaved after tip use. Tips are DNase- and RNase-free. Sterile tips are endotoxin-free. Graduated tips are marked at 10, 20, 50, 100, and 200µL.