15mL and 50mL disposable conical-bottom centrifuge tubes have been specially designed for clinical applications. Produced from a special grade of polypropylene, tubes offer exceptional clarity and chemical stability. High-density polyethylene screw-caps ensure a leak resistant tight seal. The tubes offer easy-to-read black graduation marks in 0.5mL increments and a white writing area for sample identification. Autoclavable (without caps).