Veyon Knowledge Base

What kind of centrifuge is needed for flow cytometry experiments? These 5 details determine the success or failure of the experiment Flow cytometry, as an indispensable tool in modern biomedical research, can quickly and multi-parameterly analyze the physical and chemical characteristics of single cell suspensions. From immunophenotyping and cell cycle analysis to apoptosis detection and identification of rare cells (such as circulating tumor cells), its application range covers almost every corner of the life sciences.

However, a seemingly basic but easily overlooked link - sample preparation, is often the "invisible killer" that determines the success or failure of flow experiments. In the sample preparation process, centrifugation is a key step that occurs very frequently, but the parameter selection is very particular.

Many researchers may ask: "Isn't it just centrifugation? Isn't it enough to just sink the cells?" If you think this way, you may fall into the following trap:

Increased cellular debris leads to a large number of non-specific signals in flow cytometry.

Cell activity decreases and the proportion of dead cells increases, interfering with the analysis of the target cell population.

Cells form clumps or are lost, resulting in insufficient cell numbers when running on the machine, or even clogging the flow cytometer.

The experimental results have poor repeatability, and the results done today are inconsistent with the results done tomorrow.

So, what kind of centrifuge is needed for flow cytometry experiments? As a professional centrifuge manufacturer, we will start from 5 core technical details to provide you with an in-depth analysis to help you make the most optimal decision.

1. Core lifeline: precise control of centrifugal force (g value vs. RPM) This is the most easily misunderstood and the most critical point.

Misunderstanding: Many experimenters are used to setting only the rotation speed (RPM, revolutions per minute). But what really acts on cells is the relative centrifugal force (RCF, in x g). Due to the different rotor radii of different centrifuges, the g values ​​produced by the exact same RPM on different machines may be very different. If you set your centrifuge according to "1000 RPM" in a literature, the results may be completely different.

Requirements for centrifugal force of flow cytometry: The core of flow cytometry is the analysis of single, intact, and viable cells.

Too much force: It will bring mechanical shearing force to the cells, causing damage to the cell membrane, leakage of contents, and the production of a large amount of cell debris and dead cells. These debris and dead cells can create significant background noise and autofluorescence in flow cytometry, interfering with gated analysis of live cell populations.

The force is too small: the cells cannot be completely sedimented, especially cells with small size and low density (such as lymphocytes). When the supernatant is discarded, target cells will be sucked away, resulting in a sudden drop in cell yield.

Get it right: A good centrifuge for flow cytometry experiments must be able to work accurately and stably at low to medium speed centrifugal force, usually between 150 - 400 x g (depending on the cell type).

For fragile cells (e.g. primary neurons, platelets): 150-200 x g recommended.

For common suspension cells (e.g. lymphocytes, THP-1, Jurkat): 200-300 x g recommended.

For relatively resistant adherent cells (after digestion): 250-400 x g recommended.

Key functions: The centrifuge should have a one-click conversion function between RPM and RCF (g value), and can even set the g value directly. This is a hard requirement for flow cytometry laboratories.

2. Life Guard: Mild acceleration and deceleration curve (increase/deceleration setting) This is as important as centrifugal force itself.

The root of the problem: Ordinary centrifuges have a "rough" process when starting to accelerate and brake to decelerate. The instantaneous high-speed rotation and sudden stop will generate huge shear force, tearing apart cells like a "tornado".

Special requirements for flow cytometry: In order to protect the integrity of the cells, a centrifuge dedicated to flow cytometry must have an adjustable, multi-speed acceleration and deceleration (Accel/Decel) curve.

Recommended settings: Generally choose a combination of "slow acceleration" and "slow deceleration, even without braking (free coasting)".

Why slow acceleration: Let the cells leave the bottom of the test tube smoothly and form a gradient sedimentation in the liquid evenly, instead of being instantly thrown to the tube wall.

Why slow down slowly (without braking): This is the key to protecting cells! Allowing the rotor to stop naturally by inertia can avoid the settled cells from being lifted up and scattered again by the centrifugal force to the greatest extent, thereby reducing cell aggregation and damage. The braking function of many conventional centrifuges is one of the culprits causing the shedding of cell surface antigens.

Selection suggestions for users: Please be sure to confirm whether the centrifuge you purchase has a "0" or "Off" gear in the deceleration gear (that is, free sliding stop without brake). For flow experiments, this feature is worth its weight in gold.

3. Bottom line of safety: sealing and biological safety protection (rotor and hanging basket) Samples for flow cytometry experiments come from a variety of sources, many of which have potential biological hazards (such as human blood, tissues, virus-infected cells, tumor samples, etc.). The generation of aerosols during centrifugation is one of the main routes of laboratory infection.

Core requirements:

Sealed Rotors: Biosafety sealed rotors are preferred. The cover of this rotor has a sealing ring. After the seal is tightened, even if the sample leaks, it will be locked inside the rotor. Sealed baskets (biosafety centrifuges): For horizontal rotors, each basket needs to be equipped with an airtight lid with a sealing ring. Certification standards: Centrifuges and their accessories need to pass air tightness tests with international certifications such as CAMR (Center for Applied Microbiology Research, UK) or DIN EN 61010-2-020. This is not only a compliance requirement, but also responsible for the life safety of experimental personnel.

Disinfection convenience: Can the rotor, basket, and adapter be easily removed and resistant to wiping with conventional disinfectants (e.g., 75% alcohol, 10% bleach) or high-temperature and autoclaved sterilization? This is directly related to the daily cleaning efficiency and cross-contamination control of the laboratory.

4. Pragmatism: Adaptability and Flux In flow cytometry experiments, there are various types of sample tubes. At the same time, experimental throughput varies greatly.

Adapter (compatibility): A good flow centrifuge should be easily compatible with the following common consumables by replacing the adapter:

1.5/2.0 mL microcentrifuge tube (the most common cell collection tube).

5 mL round or pointed bottom centrifuge tubes (the gold standard tubes for flow staining and washing).

15 mL and 50 mL conical bottom centrifuge tubes (for sample preparation and cell culture harvest).

96-well / 24-well deep well plates (vital for applications such as high-throughput flow cytometry, drug screening, etc.).

Selection recommendations: Swinging rotors are the first choice for flow cytometry laboratories because of their interchangeable adapters, which offer the highest flexibility. It allows the cell pellet to be concentrated in the center of the bottom, making it easier to discard the supernatant.

Flux (capacity):

Small scale/research laboratories: A benchtop centrifuge capable of centrifuging 24 x 5 mL tubes or 6 x 50 mL tubes is usually sufficient.

Large-Scale/Core Platforms: May require 48 x 5 mL or higher throughput models, or a centrifuge capable of spinning multiple microplates. If the volume of samples processed per day exceeds 100, it is strongly recommended to consider multiple centrifuges or large floor-standing models.

5. Stability and precision: temperature control and noise Cells are alive, and temperature changes and noise interference will affect the experimental results and the experience of the experimenter.

Temperature control (freezing function):

Necessity: For long-term centrifugation (>10 minutes) or temperature-sensitive cells (such as primary cells that need to remain viable, certain stem cells, cells subject to stimulatory signal transduction), a refrigerated centrifuge must be used.

Set temperature: Normally set to 4°C. Low temperature can effectively inhibit cell metabolism, reduce phenotypic changes caused by cell apoptosis or activation, and maintain the stability of surface antigens.

One tip: Even if the experiment is performed at room temperature, the friction between the rotor and the air during high-speed centrifugation will generate heat. A sophisticated temperature control system ensures that results are highly reproducible in different seasons and ambient temperatures.

Noise level: The laboratory is a workplace. Being in a high-noise environment for a long time can damage hearing and make people irritated. A well-designed centrifuge should have a no-load noise of less than 60 dBA and be as quiet as possible when fully loaded. This reflects the manufacturer's machining precision and design level.

Summary: Self-check list for purchasing a flow centrifuge The next time you purchase or evaluate a centrifuge for flow cytometry experiments, you may want to check it out with the following list:

Control accuracy: Can x g (RCF) be displayed and set directly on the panel? Instead of just RPM.

Protection functions: Is there a selectable deceleration curve (braking), especially a "no brake" option?

Biosecurity: Are there certified sealed rotors or sealed baskets? Can parts be autoclaved?

Compatibility: Can the adapter be compatible with the 1.5mL/5mL/15mL/50mL tubes commonly used in your laboratory, or even microplates?

Throughput and Temperature Control: Can the maximum capacity accommodate your peak sample volumes? Do you need Freeze function (4°C)?

Operation smoothness: Does the centrifuge vibrate a lot when it is running? Is the noise unbearable?

Centrifuges that meet all or most of the above conditions can be called "flow-friendly" centrifuges. It's not the cheapest, but it's a solid companion that can really help you get high-quality, highly reproducible streaming data.

As a professional centrifuge manufacturer, we fully understand the significance of every detail to the experiment. We not only provide precise g-value control, customizable acceleration/braking curves, and sealed rotors that meet the highest biosafety standards, but also provide a complete set of adaptation solutions from microtubes to deep-well plates.

Investing in a good centrifuge does not increase the cost, but protects every tube of your precious samples, every painstaking experiment, and every paper to be published. If you have any questions about the selection of flow-type special centrifuge, please contact us and our technical team will provide you with one-on-one professional support.