What Is an Incubator Shaker? Uses & Basics

Last verified: October 6, 2026. An incubator shaker is a laboratory instrument that combines two functions in one chamber: it holds samples at a controlled temperature, and it continuously agitates them by moving a platform in a circular or back-and-forth motion. It is most commonly used to grow bacteria, yeast, and other cultures in liquid media, where the constant movement keeps the cells suspended and supplies them with oxygen while the temperature is held steady. It is sometimes called a shaking incubator, an orbital shaker incubator, or simply a shaker.

The problem it solves is that many cultures need both warmth and mixing at the same time. A flask of growth medium left standing in a warm room would see its cells settle, its oxygen run low, and its growth be uneven. Putting that flask on a moving platform inside a temperature-controlled chamber gives every cell similar access to nutrients and oxygen, which makes growth faster and more reproducible from one run to the next.

How an Incubator Shaker Works

An incubator shaker has three main parts working together:

The chamber. An insulated enclosure, usually with a door, that holds the samples. Heating elements and a fan circulate warm air so that the temperature stays even throughout the space. Many models can also cool, which is useful for work that needs temperatures below room temperature.
The shaking platform. A flat tray that moves in a set pattern, most often an orbital motion, where it travels in a small circle. The platform carries clamps, racks, or a non-slip mat to hold flasks, tubes, or plates in place.
The controller. A panel for setting temperature, shaking speed, and often a timer. Setting the speed matters because too slow a speed gives poor mixing and aeration, while too fast a speed can cause splashing, foaming, or stress on delicate cells.

The shaking motion creates a swirling liquid surface inside the flask. That surface area exchanges gas with the air in the flask, which is how oxygen reaches the culture. This is why flask size, fill volume, and closure type all influence how well a culture grows, even at the same shaker settings.

Who Uses an Incubator Shaker, and Why

Incubator shakers are found in many kinds of labs:

Molecular biology and microbiology labs use them to grow bacterial cultures for plasmid preparation, protein expression, and general culture work.
Biotechnology and protein production labs use them to grow cells that produce a protein of interest, often before scaling up to larger systems. For the larger-scale equivalent, see what a bioreactor is.
Cell biology labs use certain models for suspension cell cultures that grow without attaching to a surface, sometimes with humidity or carbon dioxide control built in.
Biochemistry labs use them for incubations that require gentle, continuous mixing at a defined temperature, such as binding or digestion reactions.
Teaching labs use them to give students hands-on experience growing cultures.

Types and Features

Incubator shakers vary in size, capability, and design, and the differences drive what each one is best suited for:

Benchtop models are compact and sit on a lab bench. They suit small labs or smaller numbers of flasks.
Floor-standing models offer a much larger capacity and are used where many or large flasks are run at once.
Stackable units let labs double their capacity in the same floor area by placing one unit above another.
Refrigerated or heating and cooling models can maintain temperatures below ambient, which is useful for temperature-sensitive proteins or cultures.
Models with added controls may include humidity control or carbon dioxide control for particular cell types, though these features raise cost and complexity.

Shaking motion also varies. Orbital motion is the most common in culture work. Reciprocating motion moves the platform back and forth in a line, and some models can be switched between patterns. The size of the motion, sometimes called the throw or orbit, influences how vigorously a given speed mixes the culture.

How an Incubator Shaker Differs From Adjacent Equipment

Stationary incubator. Holds a controlled temperature but does not agitate. It suits plates and static cultures where mixing is not needed. A CO₂ incubator is a related still incubator used for mammalian cell lines; see the CASRAI guide on CO2 incubator calibration and temperature uniformity.
Shaker without temperature control. A bench shaker or platform shaker moves samples but does not regulate temperature. It works for mixing at room temperature but not for culture work that depends on a set temperature.
Vortex mixer. Mixes a single tube briefly and vigorously by spinning it, which is useful for quick resuspension but not for growing cultures over hours.
Bioreactor. A larger, more instrumented system that actively monitors and controls conditions such as oxygen and acidity during growth. An incubator shaker is a simpler, lower-cost step that many workflows use before moving to a bioreactor.
Water bath. Holds samples at a set temperature using heated water, sometimes with gentle shaking, but is typically used for shorter incubations rather than extended culture growth.

Practical Notes for Research-Administration and Lab-Management Readers

Procurement. Choose on capacity, temperature range, and whether cooling is needed, rather than on the lowest price alone. Think about how many flasks run at once, what sizes they are, and whether the lab will grow cultures that need temperatures below ambient. A secondhand unit can be a reasonable option if its condition is checked; see used vs. refurbished lab equipment.
Space and load. A loaded shaker is heavy and vibrates. It needs a sturdy, level bench or floor and some clearance for heat and airflow. The noise and vibration may also affect neighbors, so placement matters.
Heat and utilities. Incubator shakers add heat to a room and draw continuous power, which should be considered when planning shared lab space.
Contamination control. A warm, humid, shaking chamber is a good place for microbes to grow, including unwanted ones. Spilled medium should be cleaned up promptly and the chamber cleaned on a routine schedule. See aseptic technique for the habits that keep cultures clean.
Verification. Temperature and speed displays can drift over time. Labs that depend on precise conditions check them against independent references on a regular basis, as part of an overall equipment-management plan.
Biosafety. Shaking can create aerosols and spills, particularly if a flask closure loosens. Work with hazardous organisms calls for appropriate containment and clamping, according to institutional biosafety rules.

Choosing Settings in General Terms

The settings that matter most are temperature, shaking speed, and, for a given flask, the volume of medium it holds. Temperature is chosen to suit the organism or cell line being grown, which is usually documented in the protocol or in the supplier information for the strain. Speed is a balance between aeration and gentleness: faster mixing increases oxygen transfer but can stress fragile cells or cause foaming. Flasks are generally filled only partway so that there is enough air space and surface motion above the liquid. Flasks with baffles, which are ridges molded into the base, increase turbulence and oxygen transfer for organisms that need a lot of it, while smooth flasks are gentler. Protocol documents and supplier instructions give the specific values for a given application, and results can be compared between runs only when these settings are recorded each time.

The Short Version

An incubator shaker keeps samples at a controlled temperature while continuously moving them, which is what many liquid cultures need to grow well. It sits between a simple shaker or still incubator and a full bioreactor in both capability and cost. Culture results depend on settings, flask choice, and fill volume as well as on the instrument. For more on selecting and managing instruments like this one, see CASRAI’s broader laboratory equipment and instrumentation coverage.

This page is general information only. It is not clinical or safety training. Follow your institution’s procedures and the manufacturer’s instructions.

Frequently Asked Questions

What is an incubator shaker used for?

It is used to grow liquid cultures, such as bacteria and yeast, at a controlled temperature while shaking them so the cells stay suspended and receive oxygen.

What is the difference between an incubator shaker and a regular incubator?

A regular incubator holds a set temperature but does not move the samples. An incubator shaker adds a moving platform, which keeps liquid cultures mixed and aerated.

Why does shaking matter for culture growth?

Shaking keeps cells from settling and increases the exchange of gas between the culture and the air, so oxygen reaches the cells more evenly and growth is faster and more consistent.

Does flask size or fill level affect results?

Yes. A flask that is too full gives less surface area for gas exchange and poorer aeration. The flask type and its closure also change how much air gets in, even at the same shaker settings.

Can an incubator shaker cool as well as heat?

Some models can. Standard units usually run from a little above room temperature upward, while refrigerated or heating-and-cooling models can hold lower temperatures for sensitive samples.

Is an incubator shaker the same as a bioreactor?

No. A bioreactor monitors and controls additional conditions and is built for larger or more tightly controlled growth. An incubator shaker is a simpler instrument that many workflows use at earlier stages.