Snap Cap Centrifuge Tubes are designed for ease of use. These polypropylene tubes have flat tops for writing on, graduations, and writing area on the side of the tube. All tubes tolerate centrifugal forces up to 18,000 RCF while high speed tubes spin to 30,000 RCF. These tubes are available in a variety of colors and sizes to fit your personal needs. All tubes have a temp range of -40ºC to 121ºC. *Polypropylene is not recommended for use with Phenol Chloroform. Low temperature storage, multiple spin cycles or organic solvents can affect maximum force. Run a test before using.