Bio Plas 4155 Polypropylene 1.8mL Snap Cap Microcentrifuge Tube, Natural (Pack of 1000) Capacity: 1.8mL Made of tough, virgin-polypropylene in natural color that withstands rugged G-forces of high-speed centrifugation Snap-Cap is attached to each tube; smooth, conical interior allows the entire sample to be removed with ease and without material hangup Autoclavable at 250 degree F for 15 minutes at 15psi Use for specimen collection, mixing, electrophoresis sampling/handling, enzyme assays, radioassays, immunoassays, and many other applications