What is a Laboratory Centrifuge and How to Choose It
— Equipo JP Selecta
What is a laboratory centrifuge and how to choose it
A laboratory centrifuge is a device designed to separate the components of a liquid or suspended sample according to their apparent density. By applying a constant, high-speed rotational force, denser elements move rapidly to the bottom of the container while less dense components remain at the top, splitting into clearly distinguishable phases.
This physical principle of accelerated sedimentation is the operational basis of tasks as critical as obtaining pure serum fractions, isolating nucleic acids or concentrating cell cultures.
What is a centrifuge in the laboratory context?
Sedimentation accelerated by centrifugal force is the basis of virtually any clinical, pharmaceutical or biomedical research workflow.
How a centrifuge works: the difference between RPM and RCF
A very common technical mistake in laboratories is to assess the separating power of a unit only by its revolutions per minute (rpm).
The variable that actually determines whether a sample sediments correctly is not rotational speed alone but RCF (Relative Centrifugal Force, expressed mathematically as x g).
RCF depends on rotational speed (rpm) but also on the physical distance from the rotation axis to the bottom of the tube (rotor radius, r). Two different centrifuges running at exactly 4,000 rpm can therefore generate radically different separation forces. The standardised mathematical relationship is RCF = 1.118 × 10⁻⁵ × r × rpm².
Types of laboratory centrifuge
Each centrifuge type has acceleration, capacity and digital control specifications suited to specific workflows:
Universal centrifuges
They accept a wide range of interchangeable rotors (angular and swing-out) and adapters, allowing processing from small clinical tubes to mid-size volumes on a single unit.
Microcentrifuges
Ultra-compact benchtop devices optimised to work at high speeds with very small volumes. Specifically oriented to molecular biology microtubes (such as 1.5/2 ml Eppendorf tubes or PCR strips).
Refrigerated centrifuges
They incorporate a hermetic compressor unit that actively regulates the temperature inside the rotor chamber (typically in a −12 °C to 40 °C operating range). Essential for heat-sensitive samples.
How do you know which centrifuge your laboratory needs?
To know how to choose a centrifuge, structure the technical requirements around these six fundamental questions tied to your daily activity.
1. Define the application first, not the speed
Looking for the device with the highest nominal top speed is a frequent, unnecessary mistake. The physical nature of your sample and the standardised assay protocol dictate the ideal operating force ranges.
Recommendation: define the protocol before looking at specifications.
2. Fixed-angle rotor or swing-out rotor: they are not interchangeable
The internal geometry of the head directly influences the final layout of the pellet.
Fixed-angle (angular) rotors hold the tubes in a rigid permanent tilt (e.g. 45°); they are ideal for very high speeds and concentrate the pellet on a lateral zone at the bottom of the tube.
Swing-out rotors let the buckets move freely to a fully horizontal position during spinning. This eases contamination-free collection and is the standard choice in routine clinical applications.
3. Refrigeration: when it is essential
If your protocols usually run below 5,000 rpm with short cycle times, conventional forced-air ventilation is often enough to mitigate the thermal rise.
Active refrigeration becomes strictly essential in these cases: processing proteins, antibodies and heat-labile enzymes; biological samples for sequencing or PCR amplification; platelet processing and preparation (strict thermal control between 20 °C and 24 °C); continuous centrifugation protocols lasting longer than 20 minutes; standardised assays explicitly requiring controlled temperature at 4 °C.
4. Capacity: number of samples per cycle
To size the equipment correctly and avoid bottlenecks during activity peaks, calculate your laboratory's daily sample volume.
Load capacities vary widely: from microcentrifuges with 6-position rotors to universal units able to process dozens of 15 ml or 50 ml Falcon tubes, 96-well plates or blood bags per cycle.
Practical tip: rotor adapters flex the use of a single swing-out head to accommodate different formats and sizes without buying a new rotor for each application.
As a rule of thumb, a routine clinical laboratory with a flow of 80 to 120 daily samples will need a head with a minimum capacity of 24 positions for 10 ml tubes.
5. Noise and vibration level
In hospital, clinical or university environments where centrifuges run continuously for hours, acoustic comfort directly affects occupational health conditions.
Choosing models fitted with brushless induction motors is a smart decision: they require no maintenance for mechanical wear and drastically reduce sound emissions and vibration.
Modern JP Selecta equipment incorporates advanced elastic suspensions and internal thermoacoustic insulation that keeps sound in an optimal 50-60 dB(A) range. If the unit exceeds 65 dB(A), current occupational regulations require active hearing protection measures.
6. Applicable regulations depending on the laboratory environment
The documentary approval of the equipment must strictly align with the legislative framework of the sector in which your laboratory operates:
Clinical and IVD laboratories: the centrifuge must comply with the European In Vitro Diagnostic Regulation (IVDR 2017/746) and carry the corresponding CE marking.
Pharmaceutical industry (GMP): it should support equipment validation through cycle traceability, certified calibrations and OQ documentation.
Blood banks and haematology: units must offer stable work cycles protected against accidental modifications, in line with international recommendations.
BSL-2 or higher laboratories: it is essential to use biological safety rotors or buckets with hermetic closures to prevent aerosol release.
7. Maintenance, calibration and technical service
To maximise centrifuge lifespan and certify the validity of your analytical results, periodic preventive inspection, deep cleaning of the stainless-steel bowl and accredited speed and time calibrations must be planned.
Make sure the manufacturer offers agile official technical service and preventive support contracts: this prevents costly unplanned stops in your analytical activity.
Configure the ideal centrifuge for your laboratory
To simplify the process and find the ideal configuration interactively, use our online centrifuge configurator, designed to guide you step by step to the exact model your workflow requires. For further context on operational optimisation, read also how to improve pharmaceutical laboratory efficiency.
Open the configurator or request a no-obligation quote.