Centrifuge tubes are used to hold various liquid mixtures or liquids containing suspended solids so that they can be spun and separated in a centrifuge. The tubes are made of polypropylene, with graduations, a conical bottom, and a pressure fit cap. The capacity is 1.5ml and they are graduated from 0.1ml to 1.5ml. They are non-sterile. Sold in a case of 5000.