What Is an Orbital Shaker?

An orbital shaker moves its platform in a circular orbit, allowing liquids inside containers to mix continuously and gently.

This motion helps improve mixing and, in some applications, enhances oxygen transfer to liquid cultures.

How Does It Work?

The motor moves the platform along a fixed circular path called the orbit diameter.

Samples secured on the platform follow this motion, producing continuous mixing.

The mixing effect mainly depends on:

  • Shaking Speed (RPM)

  • Orbit Diameter (mm)

What Is Shaking Speed (RPM)?

RPM (Revolutions Per Minute) indicates how many circular movements the platform performs each minute.

  • Low RPM provides gentle mixing.

  • High RPM produces stronger agitation and increased liquid movement.

The highest RPM is not always the best choice for every sample.

What Is Orbit Diameter?

The orbit diameter is the diameter of the circular path traveled by the platform.

Common orbit diameters include:

  • 3 mm

  • 10 mm

  • 20 mm

  • 25 mm

  • 30 mm

A larger orbit creates a wider liquid movement pattern.

Why Is Orbit Diameter Important?

Two shakers operating at the same RPM can produce different mixing effects if their orbit diameters differ.

Small Orbit

Large Orbit

Gentle mixing

Stronger liquid movement

Suitable for microplates and small tubes

Suitable for flasks and culture bottles

Less foaming in some applications

Better oxygen transfer in some cultures

RPM and orbit diameter should therefore always be considered together.

Typical Applications

Orbital shakers are commonly used for:

  • Cell culture

  • Bacterial and yeast culture

  • Reagent mixing

  • Protein solutions

  • Chemical solutions

  • Food testing

  • Pharmaceutical research

  • Sample extraction

Compatible Containers

Depending on the platform and clamps, orbital shakers can accommodate:

  • Erlenmeyer flasks

  • Culture flasks

  • Beakers

  • Centrifuge tubes

  • Falcon tubes

  • Microcentrifuge tubes

  • Petri dishes (with suitable holders)

  • Microplates (with appropriate adapters)

Orbital Shaker vs. Vortex Mixer

Feature

Orbital Shaker

Vortex Mixer

Motion

Continuous orbital

Vortex motion

Number of samples

Multiple simultaneously

Usually one tube

Mixing duration

Long-term

Short-term

Cell culture

Excellent

Not suitable

Microtubes

With adapters

Excellent

What Should You Consider When Choosing an Orbital Shaker?

  • RPM range

  • Orbit diameter

  • Platform size

  • Maximum load capacity

  • Timer function

  • Digital speed control

  • Available platforms and clamps

  • Continuous-duty performance

Common Mistakes

  • Choosing only by RPM without considering orbit diameter.

  • Not securing containers properly.

  • Using excessive speed with large-volume flasks.

  • Exceeding the platform load capacity.

  • Using unnecessarily high RPM for foam-sensitive samples.

Conclusion

An orbital shaker is an essential laboratory instrument for applications requiring continuous, controlled shaking over extended periods. It is widely used for biological cultures, chemical solutions and sample preparation.

The ideal orbital shaker is selected by considering three key factors together:

RPM + Orbit Diameter + Platform Capacity

This combination helps ensure efficient, reproducible and safe mixing for a wide range of laboratory applications.