CELLTREAT Non-sterile 1.5mL Micro Centrifuge Tube. Packaged non-sterile in a case of 1000. All tubes have a frosted marking spot and engraved graduations. Attached flat top cap is easy to open and close with one hand. Centrifuge tubes can handle a temperature range of -80°C to 120°C. Manufactured from medical grade virgin autoclavable polypropylene.