Lab Manager Magazine’s Independent Guide to Purchasing a Centrifuge

Before guiding yourself through the Lab Centrifuge purchasing selection criteria below, you should ask yourself four questions related to the protocol or application you intend to use this centrifuge for.

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Before choosing a centrifuge, the first question you should ask is: floor standing or benchtop? Once you’re ready to check out the latest models, head to LabWrench.com! Narrow your search with the categories bar on the right of the LabWrench page.

Floor Standing Centrifuge

Floor Standing Centrifuges are often selected when there is either going to be a large volume of daily use or your application calls for very high G-Force speeds. They also support a very wide range of rotors so are a good choice if use of this centrifuge will likely change or need to accommodate many different or unexpected protocols. Floor Standing Centrifuges are often priced in a higher range than their benchtop counterparts. But if you are running short on bench space, the extra cost of a floor model is well justified.

Benchtop Centrifuge

The numerous options you have when it comes to Benchtop Centrifuges means that most applications can be accommodated at a lower price point than with a floor standing model. However, your sample throughput will be lower than that of a floor standing model. And if force, like that found at the very top end of the RCF, is your top priority, Benchtop Centrifuges cannot keep up with a floor standing model. You can also find very specialized centrifuges within the benchtop category that may already be perfectly tailored to your application.

Four More Questions

Before guiding yourself through the Lab Centrifuge purchasing selection criteria below, you should ask yourself four questions related to the protocol or application you intend to use this centrifuge for:

  1. How much Relative Centrifugal Force (RCF) do I require?
  2. How many samples am I going to need to process per day?
  3. What sort of tubes or microplates will the samples be contained in?
  4. Do I require special rotors, such as fixed angle or swinging buckets?

All of these questions can be answered by looking closely at the protocol you will be following. If you will be using this centrifuge for ever-changing protocols and general purpose lab use, choose based on the overall criteria presented to you that would accommodate most of your expected needs. Now that you have identified those requirements, let’s start moving through the guide and see which centrifuges best fit your needs.

1. Super Speed Centrifuge

With a RCF as high as 70,000 x g, these are the second highest g-force centrifuges available. Their large sizes also make them ideal for applications involving many users or protocols within the same unit. They typically offer a large volume range of 1.5 mL-1000 mL. Due to the size of the units, these also provide the most versatile range of configurations, with manufacturers offering a wide range of rotors. Consider a Super Speed Centrifuge if your applications involve general preparative work, such as cell separations, tissue culture, isolations of Golgi bodies and ribosomes, DNA/RNA separations and plasmid preps, to name a few.

2. Ultraspeed Centrifuge

The fastest centrifuges on the market are classified as Ultraspeed, with g-forces up to 1,000,000 x g. These units are also supported with a vast range of rotor configurations to meet your applications. Typical sample volumes range from 0.23 mL to 250 mL. Consider an Ultraspeed centrifuge if your application involves DNA, protein or RNA fractionation or lipoprotein flotation. Another common application is size gradient separations as well as many new nanotechnology applications.

3. Low Speed Centrifuge

These units are typically used in one of two specific applications; either the separation of whole cells or the whole cell harvest step when processing cultures from bioreactors. Their RCF is designed specifically for these low speed applications and usually is around 7,000 x g. Due to the limited applications, you will only find a small choice of rotors—typically supporting volumes from 1.5 mL to 2,000 mL. Low Speed Centrifuges can also be customized with special rotors and liners to outfit them for blood banking applications.

4. General Purpose Centrifuge

Due to its RCF range of up to 24,000 x g and common volume granges of 0.2 mL to 750 mL, ideal for a broad range of applications, this is the most common lab centrifuge classification. A single unit can be modified through a large selection of rotors to suit many diverse applications. If your lab is short on floor space, these units also sit nicely on an open bench. Consider a General Purpose Benchtop Centrifuge if your applications include DNA/RNA research, cell harvesting, tissue culture, protein work and sub cellular separations. But the applications these units support is almost limitless.

5. Microcentrifuge

With a similar RCF range as a General Purpose Centrifuge, up to 21,000 x g, what differentiates the microcentrifuge is sample size. Microcentrifuges are tailored for 0.2 mL PCR tubes and 1.5 mL or 2.0 mL microcentrifuge tubes. Consider a Microcentrifuge if your applications are micro volume in nature, such as daily DNA and RNA work, plasmids and mini preparation kits.

6. High Speed Benchtop Centrifuge

With a RCF almost reaching the range of a floor model, up to 50,000 x g, this centrifuge is capable of many high speed applications at a sample volume range typically between 1.5 mL to 200 mL. You will not find as many rotor options in this unit as you would in a comparable Super Speed Floor Centrifuge. Consider a High Speed Benchtop Centrifuge for applications such as whole cell harvesting or certain DNA/RNA applications.

7. Cell Washer

These are very specialized centrifuges that run at 1,500 x g and are valuable instruments for washing blood cells for antigloboulin reagent tests, such as SBO compatibility, Rh testing, cross matching and the Coombs procedure. Cell Washers typically support culture tubes in 3 mL and 5 mL volumes. Consider a Cell Washer Centrifuge if the application in your clinical or medical lab includes washing away cellular debris, extraneous proteins and other constituents of the donor blood from red blood cells.

8. Clinical Centrifuge

This low-throughput centrifuge is used on a daily basis in most clinical labs and hospitals. They spin at an RCF of 3,000 x g or lower while holding 3 mL to 15 mL sample tubes. A typical run can process between 4 to 28 tubes. Consider a Clinical Benchtop Centrifuge if your applications include spinning blood collection tubes and urine samples at very low speeds for diagnostics.

Categories: Purchasing Guides

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Published: September 1, 2009

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