Thermo Scientific™ Nunc 15mL & 50mL Conical Sterile Polypropylene Centrifuge Tubes are premium, high-quality conical tubes that are environmentally friendly, offer the highest cleanliness with a recyclable plastic rack and allow for increased traceability with the largest writing area on the market. Nunc Labware Products are made from high-purity resins and molded using our state-of-the-art processes. Plastic labware is a safer alternative to glass without sacrificing accuracy.