Freezing tubes are available in volumes of 0.5, 1.5, 1.8, and 5.0 ml from Biostar Lifetech. They are manufactured from durable PP and PE, can be frozen at -80°C, and have interlocking caps to prevent contamination. The tubes have accurate graduations, color-coded caps, and areas for labeling. They are gamma radiation sterilized and packaged in bags with lot numbers.