How Fast Is A Centrifuge

RCF Centrifuge Some researchers mistakenly call back that RPM and RCF refer to the same thing. Well, while these two units are both used to ascertain the speed of a centrifuge, not knowing the divergence betwixt them will lead to disastrous results. You wouldn't desire that for sure! And then, to eliminate defoliation and preserve the integrity and accurateness of your experiments, here's everything you need to know about RPM, RCF, and Thou-force.

RPM vs. RCF: Where Lies the Difference?

RPM (revolutions per minute) basically describes how fast the centrifuge goes. This is the unit centrifuge manufacturers utilise to inform users how fast the rotor revolves.

On the other hand, RCF (relative centrifugal force) refers to the amount of acceleration or force exerted on the sample in a centrifuge. In other words, information technology is a function of the rotational speed of the rotor and the radius of the rotation. RCF is expressed in multiples of the standard acceleration due to the globe'southward gravitational field (times gravity or x g) so don't be surprised if you lot see RCF and "x g" (m-force) used interchangeably in most centrifugation protocols.

Which Should You lot Use?

Based on the to a higher place definitions, it is easy to see that RPM and RCF are two entirely different things. And since dissimilar centrifuge machines may have different rotor sizes, using RCF or g-force will give y'all the right setting for your experiments.

Notwithstanding, some centrifugation protocols provide instructions in RPMs, not in RCF. Likewise, older centrifuges practice not have an automated converter. This can be a problem since some procedures call for precise centrifugation weather condition, and not meeting those weather will lead to erroneous results. Don't worry. In that location is an easy fix to this problem. You just demand to convert the given RPMs to RCF (and vice versa) using these formulas:

1000 = (rpm)² × 1.118 × 10^-5 × r

RPM = √[RCF/(r × ane.118)] × 1 × x⁵

where g refers to the relative centrifugal strength (RCF), r is the radius of the rotor (cm), and Northward is the speed of the centrifuge in revolutions per minute (RPM).

Annotation: To determine the radius of your centrifuge rotor, simply have the measurement from the heart of the centrifuge rotor to the end of the test tube carrier.

It is interesting to note that centrifugation speed and time may not be as critical in routine sample-handling procedures involving the use of benchtop microcentrifuge. In these cases, information technology does not matter if you lot employ a faster speed or centrifuge your samples longer than necessary. What'southward more than of import is that the cells, debris or resin are pelleted effectively. As such, many protocols merely utilise some general guidelines without specifying a particular centrifugal force.

Converting RPM to RCF the Piece of cake Mode

While the higher up equation comes quite handy, you can besides make conversions by:

Referring to websites that provide information on particular centrifuge models and rotor heads. You will go the most precise results by using this method. Hither are some useful resources that you can use – Gene Infinity (for Beckman, Sorvall, and Thermo Scientific), Endmemo (for Beckman, Sorvall and Eppendorf), and Science Gateway (for Beckman, Sorvall, Blended, Eppendorf, Piramoon and custom rotors).
Using an online converter (e.g., Insilico , Hettich , Encore Bio).

Using nomogram (nomograph, alignment chart, abaque), a graphical calculator that can help you lot determine the correct speed of a centrifuge rotor to achieve your desired RCF. This volition give you an accurate estimate useful for depression speed centrifugation applications. You can download and print one for your personal use from these websites – DJB Lab Intendance , Optics Planet .