In centrifugation the clearing factor or k factor (in hours) required for sedimentation of a fraction with a known sedimentation coefficient (in svedbergs):

The value of the clearing factor depends on the maximum angular velocity of a centrifuge (in rad/s) and the minimum and maximum radius of the rotor:

As the rotational speed of a centrifuge is usually specified in RPM, the following formula is often used for convenience:

Centrifuge factor of a centrifuge-rotor combination.

factor has to be adjusted:

1. 2

by the formula:

is a constant for a certain particle, this relationship can be used to interconvert between different rotors.

, the time to pellet in the other rotor, can be calculated. In this manner, one does not need access to the exact rotor cited in a protocol, as long as the K-factor can be calculated. Many online calculators are available to perform the calculations for common rotors.

References

External links

• Beckman Coulter lab resources and manuals

• Appendix F of the Cell Biology Laboratory Manual