Lab Manager Magazine's Independent Guide to Purchasing a Lab Shaker, Mixer or Stirrer
By John Buie
There are many different factors to consider when purchasing a lab shaker, stirrer or mixer, as well as countless makes and models to choose from. The following guide can make your decision a little easier, giving information about the various types before you visit LabWrench.com to check out the latest models.
Lab Shakers are primarily used for culturing organisms in shake flasks or test tubes, and can also be used for mixing liquids. When choosing a Lab Shaker you should consider the type, quantity and size of your flasks and test tubes. Shakers range from small to mid-size benchtop models, larger-capacity console (floor standing) models, or space-saving stackable models. Heavier loads may also require a heavy-duty drive mechanism such as a triple-eccentric drive vs. a lighter-duty single-eccentric drive. Lab shakers are available in two different mixing actions: orbital and reciprocal. The next step in this guide will help you choose which is best for your needs. NOTE: Some manufacturers make a combination reciprocating/orbital shaker.
Orbital Shakers are ideal for culturing cells by imparting gentle to vigorous agitation in a smooth, circular motion, typically in a speed range of 40 to 500 rpm. Many models are offered with built-in temperature control (see incubating/refrigerating shakers at right), while others can be placed directly inside incubators or in cold or warm rooms. Most models can be used with interchangeable platforms to support a range of flasks, tubes, beakers or bottles. Different flasks and/or tubes can be accommodated on the same platform.
Digital Orbital Shakers have a digital control panel, display and microprocessing unit which offers precise and reproducible management of agitation speed and running time.
Analog Orbital Shakers are adjusted by mechanical dials on the front of the unit and are suitable for many common lab tasks.
Reciprocal Shakers are typically used for mixing liquids and provide gentle to vigorous agitation in a reciprocal mixing motion that pushes the liquid from one side of the beaker to the other.
Digital Reciprocal Shakers have an added digital control panel, display and microprocessing unit. With this function they are able to be programmed to operate at various lengths of time and speed settings.
Analog Reciprocal Shakers are adjusted by mechanical dials on the front of the unit and are suitable for many common lab mixing needs.
Incubating/Refrigerating Shakers should be considered if you require a shaker with temperature control. They can either cool down or heat up the shaking materials as required. A series of small fans inside the shaker’s enclosure ensures uniform temperature dispersion. The size will range from a benchtop unit to a floor model as well as a stackable option, which can handle larger capacities in a smaller space. There are several choices of interchangeable platforms to accommodate any combination of lab needs. Different sized flasks and racks can be used on the same platform as well. Some models offer multi-step programming, allowing the user to incubate and/or refrigerate at predetermined time intervals.
Digital Incubating/Refrigerating Shakers have a digital control panel, display and micro-processing unit. With this function they are able to be programmed to operate at various lengths of time and speed settings. For more advanced controls, look for models which offer multi-step programming. With this function they can also be programmed, depending on the model, to perform functions ranging from simple programming of start/stop, temperature and speed; or capable of multi-step programs with auto-ramp up/down of speed, temperature and even photosynthetic lighting.
Analog Incubating/Refrigerating Shakers are adjusted by mechanical dials on the front of the unit and are suitable for many common lab mixing needs.
Magnetic Lab Stirrers mix liquids by moving a stir bar with a magnet, or series of electromagnets, to create a rotating magnetic field that spins the stir bar immersed in the liquid. Magnetic lab stirrers are available with a heated platform or a non-heated platform.
Heated Magnetic Lab Stirrers consist of a hot plate and magnetic stirrer in one. They feature adjustments to control both the platform temperature and the mixing speed. These come in single-position or multi-position platform units.
Multi-Position Heated Magnetic Lab Stirrers will heat and mix multiple beakers or flasks at a time in more than one position on the platform.
Single Position Heated Magnetic Lab Stirrers will heat and mix one beaker or flask at a time in one position on the platform.
Non-Heated Magnetic Lab Stirrers do not contain a heating element in the platform. The speed at which they rotate the spin bar is adjustable. These come in single-position or multi-position platform units.
Multi-Position Non-Heated Magnetic Lab Stirrers will mix multiple beakers or flasks at a time in more than one position on the platform.
Single Position Non-Heated Magnetic Lab Stirrers will mix one beaker or flask at a time in one position on the platform.
Overhead Lab Stirrers are available in a variety of motor speeds measured in horsepower. If you are purchasing an overhead stirrer for general lab use make sure to invest in one with enough horsepower to mix the largest volume and thickest viscosity you anticipate.
Mechanical Overhead Stirrers often have two or more speed settings based on the viscosity of the material to be mixed. A wide range of paddles, clamps, tube holders and stands are available to suit your mixing needs.
Electronic Overhead Stirrers are very similar to mechanical overhead stirrers but have an added digital control panel, display and processing unit. With this function they are able to be programmed to operate at various time lengths and speed settings. Units with micro-processor speed controls also maintain a more constant speed.
Vortex Mixers are ideal for vigorous agitation from 200 to 3,200 rpm in a vortex mixing motion. On some models the platform can be interchanged to support a single tube for intermittent use or a platform for a range of capped or sealed containers. Most will operate in either touch mode or continuous operation.
Basic Vortex Shaking Mixers are adjusted by mechanical dials on the front of the unit and are suitable for many common lab mixing needs.
Digital Vortex Shaking Mixers have an added digital control panel, display and micro-processing unit. With this function they are able to be programmed to operate at various time lengths and speed settings.
New Brunswick Scientific manufactures over two dozen models of biological shakers to suit a wide variety of applications and budgets. Models include open air, incubated or refrigerated systems in benchtop to space-saving stackable styles. Top-of-the-line Innova® Shakers feature our often imitated but never duplicated Triple-Eccentric Drive for uniform motion and superb reliability. Innova shakers handle heavier workloads, provide precise setpoint control, and are offered with advanced programming capabilities. Optional features include photosynthetic lighting, gassing, humidity monitoring, and UV germicidal lights. Or, select from our economical Excella® Shaker line, featuring microprocessor controls (and one analog controlled model) with counterbalanced drives for accurate control and dependable operation. www.nbsc.com/LMF
Heidolph Instruments, founded in 1938 as a manufacturer of precision drive motors and engineering, is a manufacturer of High Quality laboratory equipment, specializing in rotary evaporation, shakers, overhead stirrers, peristaltic pumps, and magnetic hotplate stirrers. We believe in “Research made easy” and all Heidolph products come with a 3 year warranty. Heidolph Brinkmann was formed as our North American headquarters and includes exclusive partnerships for Tuttnauer™ autoclave sterilizers, Radleys™ synthesis solutions, and AirClean™ laboratory ventilation solutions. Our Chicago area office provides National Customer Service, Product Repair, Technical Support, Warehousing, and Field Sales Management. www.heidolph.com
IKA® celebrates 100 years of excellence creating laboratory equipment globally and 25 years in the US. The IKA® Group is a global market leader for laboratory equipment, analytical and process technology. Magnetic stirrers, overhead stirrers, dispersers, shakers, mills, calorimeters, laboratory reactors and incubation shakers make up the laboratory and analytical equipment’s portfolio. While the process technology section offers solutions for production scale stirring, mixing and kneading applications. The company is headquartered in Staufen, Germany. Subsidiaries located in USA, China, India, Malaysia and Japan. www.ika.net
For over 25 years, Labnet has proudly served the Life Science, Clinical and Industrial Laboratory Markets. As a leader in Benchtop Shaking Equipment, Labnet has a wide array of models that includes Vortexers, Orbital Shakers, 3D Mixers, Rockers, Reciprocal Shakers and Rotators. These instruments incorporate the latest in motor drive and motor control technology for long term reliability and ease of use. Recent additions to the line include the EnduroTM MiniMix and the award winning Revolver Rotator. Contact Labnet’s technical support department for help choosing a model that best suits your specific requirements. www.labnetlink.com