By Donal O’Sullivan, BSc. Reviewed by Michael Anderson, MBA.

Choosing a microcentrifuge or small benchtop centrifuge should start with the laboratory workflow, not the maximum speed printed on the specification sheet. The right centrifuge needs to accommodate the tubes and samples you actually use, provide the required relative centrifugal force (RCF), offer suitable rotor capacity and configuration, and support any temperature-control or operational requirements of the method. For many laboratories, the practical decision is therefore a combination of sample and tube format, required RCF, throughput, rotor configuration, refrigeration and workflow controls. Defining these requirements before comparing individual instruments makes it easier to identify technically suitable options without paying for capabilities that the workflow does not require.

 

Key Takeaways

• Start with the sample, workflow and tube format, then determine the centrifuge specification required.
• Compare centrifuges using the RCF required by the method, rather than maximum RPM alone.
• Check the actual rotor configuration, tube capacity and adapter requirements rather than assuming that a nominal tube size will fit.
• Consider throughput as well as capacity: the number of tubes processed per run can materially affect routine laboratory efficiency.
• Choose refrigeration when the sample, method or validated procedure requires temperature control, not simply because a refrigerated model is available.
• Once the technical requirements are defined, compare controls, footprint, accessories and other practical features before moving to individual models.

Start with the Workflow, Not the Centrifuge

A useful first question is not Which centrifuge should we buy? but:

What does the laboratory need the centrifuge to do?

That distinction matters because apparently similar benchtop centrifuges can be designed for quite different workloads. A compact unit intended primarily for quick spin-downs is not necessarily suitable for a method requiring higher RCF, controlled run times or larger tube formats. Conversely, purchasing substantially more centrifuge capability than the workflow requires may add cost and complexity without improving the result.

Begin by documenting the routine work the instrument will support:

• What samples will be centrifuged?
• Which tube formats are used?
• What RCF does the method or protocol require?
• How many tubes normally need to be processed at once?
• Is temperature control required?
• Does the sample require a sealed or aerosol-tight rotor, bucket or lid, or any other defined containment feature?
• Are timed or repeatable runs important?
• Are multiple workflows expected to share the instrument?

The answers create a basic user requirement against which candidate centrifuges can be assessed.

This is particularly useful when a centrifuge will be shared. The most demanding legitimate workflow may determine part of the required specification, but that does not mean every maximum specification should be increased. Requirements should be based on actual laboratory needs.

Match the Centrifuge to the Tube and Sample Format

Tube format is one of the most useful starting points because it immediately narrows the range of suitable equipment.

A laboratory working predominantly with 0.2mL PCR tubes or 1.5/2.0mL microcentrifuge tubes has different equipment requirements from one routinely processing 15mL or 50mL conical tubes.

A practical first-pass framework is:

Routine format	Typical equipment consideration	What to establish before selection
0.2 mL PCR tubes	Compact centrifuge or suitable microcentrifuge configuration	Required RCF, PCR-tube or strip compatibility, rotor supplied and any adapters required
0.5 mL microtubes	Microcentrifuge or compatible compact centrifuge	Required RCF, direct fit or adapter requirement, tubes per run
1.5/2.0 mL microcentrifuge tubes	Microcentrifuge	Required RCF, rotor capacity, throughput and control requirements
5 mL tubes	Compatible small centrifuge	Exact tube dimensions, rotor compatibility, capacity, adapters and required RCF
15 mL conical tubes	Small benchtop centrifuge with appropriate rotor	Required RCF, number of tubes per run, rotor configuration and tube support
50 mL conical tubes	Benchtop centrifuge with appropriate capacity	Required RCF, rotor configuration, number of tubes per run and available space

This is a selection framework rather than a statement that every tube of a given nominal volume is interchangeable. Actual tube dimensions, construction, rated operating limits and the centrifuge manufacturer's rotor and adapter specifications still need to be checked.

Where a laboratory has not yet established whether 15 mL or 50 mL tubes best suit its workflow, our guide to choosing between 15mL and 50mL centrifuge tubes addresses that decision separately.

For molecular biology and PCR applications, tube requirements may also be application-specific. See Choosing Centrifuge Tubes for Molecular Biology and PCR Workflows for the consumables side of that decision.

Determine the Required RCF

Once the sample and tube formats are understood, establish the relative centrifugal force required by the workflow.

This is more useful than selecting a centrifuge primarily by its maximum revolutions per minute (RPM).

RPM describes rotational speed. RCF expresses the centrifugal acceleration applied to the sample relative to Earth's gravitational acceleration and depends on both rotational speed and rotor radius. Two centrifuges operating at the same RPM can therefore generate different RCF values.

If a method specifies an RCF, that should normally be the relevant performance requirement when assessing whether a centrifuge can perform the method.

The objective is not simply to purchase the instrument with the largest maximum RCF. Instead ask:

1. What RCF does the intended workflow require?
2. Can the proposed centrifuge and relevant rotor achieve it?
3. Can the intended tubes withstand the required conditions when used in the specified configuration?
4. Does the instrument provide the level of control required for the workflow?

A centrifuge capable of generating a high RCF does not automatically make every tube that physically fits the rotor suitable for operation at that force. Confirm the tube manufacturer's maximum RCF and the conditions attached to that rating, including the required rotor or carrier support and any applicable limitations relating to temperature, fill volume, sample or liquid properties and run duration. Where actual conditions differ from those used to establish the rating, the published maximum RCF may not apply.

For a more detailed explanation of these relationships, see Understanding RCF, RPM and Rotor Compatibility for Centrifuge Tubes.

Check Rotor Configuration, Capacity and Adapters

A centrifuge specification cannot be assessed properly without considering the rotor.

The rotor determines which tubes can be accommodated, how many can be processed and, together with the instrument, the operating conditions available to the laboratory.

Rotor geometry may also be method-relevant. Where the workflow depends on tube orientation, pellet location or preservation of interfaces during centrifugation, confirm whether a fixed-angle, swinging-bucket or other specified rotor configuration is required rather than treating different rotor types as interchangeable solely because they accept the same tube.

Check the actual configuration being supplied rather than assuming that every rotor or adapter shown for an instrument is included as standard.

Questions to ask include:

• Which rotor is supplied with the centrifuge?
• How many tubes does it accommodate?
• Which tube formats and dimensions are supported?
• Are adapters required?
• If adapters are needed, are they supplied or purchased separately?
• What operating limits apply to the relevant rotor and configuration?
• Will another rotor be needed for a second workflow?

Where samples, spills, cleaning agents or disinfectants may expose the rotor, adapters, lids or seals to aggressive chemicals, confirm that the relevant materials are compatible with those substances and with the laboratory's intended cleaning or decontamination procedure. Chemical exposure can damage rotor and accessory materials even where the sample tube itself remains compatible.

This becomes particularly important when one centrifuge is expected to handle several tube formats.

An instrument may appear flexible because additional rotors or adapters are available, but the laboratory should distinguish between possible configurations and the configuration actually being purchased.

Capacity should reflect routine workload

Maximum tube capacity is also not necessarily the same as appropriate capacity.

Consider a laboratory routinely processing 18 microtubes at a time. A centrifuge accommodating only a small number per run may technically perform the separation but require multiple cycles. The operational impact can become significant when repeated several times each day.

Conversely, a larger-capacity instrument may offer little benefit if most runs contain only a few samples.

Estimate:

typical tubes per run × expected runs per day

and consider peak workloads where these are genuinely relevant.

The objective is sufficient practical capacity without automatically selecting the largest available instrument.

Decide Whether Refrigeration Is Required

Refrigerated centrifuges can be important where temperature control is necessary for the sample, method or established laboratory procedure. Refrigeration should therefore be treated as a technical requirement to establish, not a default upgrade.

Ask:

• Is the sample temperature-sensitive under the intended centrifugation conditions?
• Does the method specify a controlled temperature?
• Is temperature control required by an established or validated procedure?
• Are run duration and operating conditions likely to make temperature control important?
• Is the laboratory replacing an instrument within an existing controlled workflow?

Where the answer is no, a non-refrigerated centrifuge may be entirely appropriate.

Where temperature control is genuinely required, confirm the relevant instrument's temperature range, temperature-control performance and applicable operating conditions from authoritative manufacturer documentation rather than assuming that all refrigerated centrifuges provide equivalent performance. Do not assume that the displayed or selected chamber temperature is necessarily the temperature reached by the sample throughout the run; where sample temperature is method-critical, establish any required rotor pre-cooling or other manufacturer-specified temperature-control procedure.

This distinction can materially affect both equipment specification and purchase cost, so it is worth resolving before individual models are compared.

Consider the Controls Needed for Routine Work

After establishing tube format, RCF, rotor configuration and temperature requirements, consider how the centrifuge will actually be operated.

Useful features depend on the workflow rather than on the length of the specification sheet.

RCF and RPM control or display

Where methods are expressed in RCF, the ability to work directly with RCF can simplify routine operation. Whatever interface is provided, users still need to understand the relationship between the method requirement and the selected rotor configuration.

Timer and continuous operation

A timer is useful where centrifugation duration is controlled as part of a method. Check that the available time range and operating modes suit the intended work.

Acceleration and deceleration control

Some methods require controlled acceleration or deceleration, including reduced braking or no braking, to avoid disturbing pellets, gradients or separated layers. Where the procedure specifies an acceleration or braking condition, confirm that the centrifuge provides the required control rather than assuming that speed and run time alone define the centrifugation step.

Quick-spin operation

Quick-spin or pulse-type operation can be useful for brief spin-down workflows, but it should not be confused with the controlled centrifugation requirements of methods specifying particular force and duration conditions.

Programmable operation

Stored programmes may be valuable where laboratories repeatedly use defined settings or where several users share an instrument. They may offer much less value in a laboratory performing only occasional straightforward spin-downs.

Safety and imbalance controls

Review the actual safety and monitoring features of shortlisted instruments and their operating instructions. Do not assume that similarly positioned centrifuges have identical controls.

The general principle is simple: select controls that improve safe, repeatable operation of the workflows the laboratory actually performs.

Consider the Practical Fit in the Laboratory

Technical performance is only part of equipment suitability.

A small benchtop instrument still needs an appropriate location, electrical supply and sufficient working space. Manufacturer requirements for installation, ventilation, clearances and operating environment should be checked before purchase.

Other practical considerations may include:

• available bench space;
• instrument dimensions and weight;
• access around the instrument;
• noise where the centrifuge will operate close to occupied work areas;
• ease of rotor or adapter changes where several workflows share the instrument;
• cleaning requirements;
• availability of required rotors and adapters;
• manufacturer-specified inspection, maintenance and replacement requirements for the rotor, seals and other safety-critical accessories, including any defined service-life limits;
• documentation needed by the laboratory;
• warranty and support arrangements.

For regulated, accredited or validated workflows, also establish whether the supplier or manufacturer can provide the calibration, performance verification, qualification services and traceable documentation required by the laboratory's quality system. These requirements should be defined before purchase where centrifuge speed, time or temperature performance forms part of a controlled method.

These factors should generally be assessed after technical suitability has been established. A smaller footprint or lower purchase price does not compensate for an instrument that cannot safely perform the required workflow.

A Practical Centrifuge Selection Framework

Rather than comparing product specifications immediately, work through the selection in a controlled sequence.

Step	Question	Selection outcome
1. Workflow	What samples and processes will the centrifuge support?	Defines the actual laboratory requirement
2. Tube format	Which tubes must be accommodated?	Narrows appropriate centrifuge and rotor configurations
3. Required RCF	What centrifugal force does the workflow require?	Establishes the necessary performance range
4. Throughput	How many tubes need to be processed per run and per day?	Establishes practical rotor capacity
5. Rotor/configuration	Which rotor and adapters support those tubes and conditions?	Confirms physical and operational suitability
6. Temperature	Does the workflow require controlled temperature?	Determines whether refrigeration is required
7. Controls	Which timing, display, programming or other operational controls are genuinely useful?	Defines practical operating requirements
8. Laboratory fit	Does the instrument fit the available space and operational environment?	Confirms practical suitability
9. Commercial comparison	Which technically suitable options best meet the laboratory's remaining purchasing requirements?	Creates a defensible shortlist

This sequence helps prevent a common purchasing problem: comparing headline specifications before defining what the laboratory actually needs.

For laboratories primarily requiring microtube centrifugation, the next commercial step is to explore laboratory microcentrifuges. Where the required tube capacity or configuration extends beyond that equipment class, the broader laboratory centrifuges range provides the more appropriate starting point.

Pre-Purchase Centrifuge Specification Check

Before requesting quotations or comparing individual instruments, record the laboratory's requirements.

Requirement	Laboratory specification
Samples/workflows
Required tube formats
Required RCF or operating range
Typical tubes per run
Peak capacity requirement
Required rotor configuration
Required adapters
Refrigeration required?
Timing/control requirements
Quick-spin requirement
Programme requirements
Available bench space
Required documentation
Other laboratory-specific requirements

This specification does not need to be complicated. Its purpose is to separate requirements from preferences.

A feature should be treated as essential when the workflow genuinely depends on it. Other features can then be evaluated as preferences when technically suitable instruments are compared.

That approach also makes discussions with different suppliers more consistent because each candidate can be assessed against the same underlying laboratory requirement.

Choosing the Right Centrifuge: The Main Principle

The most appropriate microcentrifuge or small benchtop centrifuge is not necessarily the fastest instrument or the model with the longest feature list.

It is the centrifuge whose tube capacity, rotor configuration, achievable RCF, temperature capability and operational controls match the laboratory's actual workflow.

Start by defining those requirements. Then compare technically suitable instruments against the same specification.

This provides a more reliable basis for purchasing decisions and reduces the risk of selecting an instrument because of headline specifications that have little relevance to its intended use.

Explore More

• Laboratory Microcentrifuges — explore equipment for microtube and related small-volume centrifugation workflows.
• Laboratory Centrifuges — explore the broader centrifuge range where capacity or workflow requirements extend beyond microcentrifuges.

Frequently Asked Questions

What should I look for when choosing a microcentrifuge?

Start with the tube formats, required RCF and number of samples you need to process. Then check rotor configuration, capacity, adapter requirements, temperature requirements and the operational controls needed for the workflow. Compare individual instruments only after these technical requirements have been established.

Should I compare microcentrifuges by RPM or RCF?

Use the RCF required by the workflow as the more relevant performance criterion where the method specifies centrifugal force. RPM alone is not directly comparable between different rotor configurations because the RCF generated also depends on rotor radius.

Do I need a refrigerated microcentrifuge?

A refrigerated microcentrifuge is appropriate when the sample, method or established procedure requires temperature control during centrifugation. Refrigeration should not automatically be treated as necessary for every laboratory workflow; establish the actual temperature requirement before selecting the instrument.

Can the same centrifuge be used with different tube sizes?

Potentially, but only where the centrifuge, rotor and any required adapters are specified for those tube formats and operating conditions. Do not assume that a tube is suitable simply because it can physically be placed in a rotor or adapter.

How much centrifuge capacity does a laboratory need?

Choose capacity according to realistic routine and peak workloads rather than maximum capacity alone. Consider the typical number of tubes per run, expected runs per day and whether multiple workflows will share the centrifuge. An undersized rotor can create unnecessary repeat runs, while unused capacity may provide little practical benefit.

Read More

• Understanding RCF, RPM and Rotor Compatibility for Centrifuge Tubes
• 15ml vs 50ml Centrifuge Tubes – How to Choose the Right Volume for Your Workflow
• Choosing Centrifuge Tubes for Molecular Biology and PCR Workflows

 

 

Written by: Donal O’Sullivan, BSc, Co-Founder and Sales Director, LabFriend UK. Donal brings deep chemistry-led technical expertise across analytical chemistry, biochemistry, environmental monitoring, laboratory instrumentation, consumables and scientific product selection.

Reviewed by: Michael Anderson, MBA, Founder and Managing Director, LabFriend UK. Michael reviews LabFriend UK content for customer relevance, commercial accuracy, operational practicality and alignment with LabFriend UK’s laboratory supply model.