Centrifuge Simulator
How to use the centrifuge simulator
- Set the speed in RPM and the rotor radius. The rotor spins and the × g, the relative centrifugal force on the samples, is shown.
- Watch the red particles sink to the bottom of the tubes and form a pellet. Larger particles or more force pellet faster.
- Note that the same RPM gives more force in a bigger rotor: that is why protocols give × g, and the RCF to RPM Converter converts between them for your rotor.
Frequently asked questions
What is the difference between RPM and RCF?
RPM is how fast the rotor turns. RCF, written × g, is the force on the sample as a multiple of gravity, and it depends on the rotor radius too: RCF = 1.118 × 10⁻⁵ × r (cm) × RPM². The guide on converting RPM to g covers it, with a table of common settings.
Why do bigger particles pellet faster?
Sedimentation speed is proportional to the centrifugal force and to the square of the particle's radius (Stokes' law), and to the difference in density between the particle and the liquid. Cells pellet in a minute at a few hundred × g; proteins and viruses need hours at 100,000 × g in an ultracentrifuge.
Is the spinning speed in the picture real?
No. At thousands of RPM a real rotor is a blur, so the animation turns at most a few times a second. The force and the pelleting rate are computed from the real RPM.
It says WebGL is turned off.
The 3D view needs WebGL, which every current browser has. It can be switched off by hardware acceleration being disabled in the browser settings, or by a very old graphics driver. Turn hardware acceleration on, or try another browser.
Is anything uploaded?
No. The simulation is drawn by your own browser with WebGL; nothing is sent anywhere, and it keeps working offline once the page has loaded.