FAQ - Tubes
1. Can Cryo.S vials be stored in liquid nitrogen?
Yes. GREINER offers internally threaded Cryo.S vials that are liquid nitrogen compatible. (We recommend internally threaded over externally threaded tubes for liquid nitrogen storage in case of accidental submersion in the liquid phase.) Special note: Most people do not differentiate between the liquid and gas phase of liquid nitrogen storage. However, it is important to remember that liquid nitrogen storage typically implies gas phase storage. The dewer is typically filled to a certain level with liquid nitrogen and the baskets holding samples normally sit above this level. Submersion in the liquid phase for extended periods of time may cause the tube to crack or become brittle
2. What are RPM, RCF, and g force and how do I convert between them?
The magnitude of the radial force generated in a centrifuge is expressed relative to the earths gravitational force (g force) and known as the RCF (relative centrifugal field). RCF values are denoted by a numerical number x g (ex. 1,000 x g). It is dependent on the speed of the rotor in revolutions per minute (RPM) and the radius of rotation. Most centrifuges are set to display RPM but have the option to change the readout to RCF. To convert between the two by hand, use the following equation: RCF = 11.18 (r) (rpm/1000)2 Where r = the radius of the rotor in centimeters.
3. What is the maximum speed at which GREINER 15 mL and 50 mL centrifuge tubes can be spun?
The 15 mL polypropylene tubes can be safely spun up to 13,000 RCF in a supported rotor and 3,500 RCF in a non-supported rotor. The 50 mL polypropylene tubes can be safely spun up to 9,500 RCF in a supported roter and 3,200 in a non-supported rotor.