Graduated Microcentrifuge TubesGraduated Microcentrifuge Tubes Thomas microcentrifuge tubes are designed to provide secure, leakproof seals while remaining easy to open. Polypropylene tubes are autoclavable to 120C at 15 psi for 15 minutes. 1. 5 mL tubes are graduated at 0. 1, 0. 5, 1. 0 and 1. 5 mL. Features: Virgin polypropylene construction Fit 80 well freezer racks Autoclavable Graduated Non sterile Certified RNase and DNase free Frosted writing area on tubes and caps Freezable