Polypropylene with highest translucence. For the storing and conservation of tissue cultures and biological samples e.g. sera, blood and spermata. For applications to 190°C in the gaseous phase of liquid nitrogen or in freezers. The tubes are produced in a class 7 clean room (class 10000) according to DIN ISO 13485:2004, ISO 14644 and 14698 (Federal Standard 209).