The triple thread of the 0.30ml tube with external thread gives an excellent closure and horizontal placement of the cap to ensure longterm sample preservation and storage. Screw caps are available in six different colors.    
   
Using externally threaded storage tubes eliminates the possibility of the sample coming into contact with the screw thread, minimizing chance of cross-contamination while improving sample integrity. Due to thick tube walls, the tube has a sturdy design and excellent properties for ultra-low temperature storage.    
   
These sample tubes can hold a higher (net) volume of material while occupying the same amount of storage space, maximizing storage volume. The code surface of the tubes with external thread features a raised edge, which protects the 2D code against accidental scratches, ensuring absolute traceability.