Made of polypropylene. Certified RNAse, DNAse and pyrogen free. The strip includes 8 integral 0.2 tubes with ultra thin sidewalls and bottoms with individually attached caps. With flat (needle pierceable) individually attached hinged caps. Every cap embodies a shield in order to prevent contamination when being opened. While easily opened and closed with one hand, their positive sealing will fully protect the contents from evaporation during the whole thermal cycle. These strips can be cut to any length while each tube has its own attached cap.