A Quick Guide to Lab Homogenizers
Laboratory homogenizers are among the most versatile tools in research. Lab homogenizers are virtually indispensible because they help scientists efficiently evaluate various approaches to mixing, dispersing, cell disrupting, emulsifying, particle reduction and similar exercises. The objective is developing efficient homogenizing procedures that can be scaled to commercial production levels.
Selecting a Homogenizer Mixer
Homogenizer mixers are manufactured in a variety of configurations generally classified by speed in RPM and power in watts. These specifications relate to the homogenizer drive unit, which much like an electric drill operates what is called the rotor-stator assembly. Sample viscosity and volume will help you determine the power performance specifications in the homogenizer drive unit, with viscosity being the primary consideration. At one end of the scale a hand-held homogenizer drive operates at 125 watts power and is designed for samples from 0.1 ml to 1 liter.
At the other end you can select a 1700-watt high-powered homogenizer drive to disperse samples from 10 to 20 liters in volume. The higher powered models should be attached to an adjustable mounting support to hold them steady at a slightly offset position in the sample container. The offset position helps avoid a whirlpool effect that interferes with the dispersing action.
Homogenizer drive motor speed is another purchasing criterion. Today’s laboratory homogenizers are available with variable speed control, an extremely useful function especially to avoid splashing samples out of beakers or other containers. Start at the lowest speed and ramp up to the desired speed. In the models cited above the smaller unit operates from 15,000 to 35,000 rpm while the largest from 5,000 to 22,000 rpm.
The Business End of a Lab Homogenizer
The rotor-stator assembly mentioned above is what does the actual homogenizing. Powered by the drive motor the rotor rotates (of course!) inside the stationary stator affixed to the drive motor housing. There are myriad rotor-stator designs, the selection of which is governed by the volume and viscosity of what is being done: mixing, shearing, tearing, dispersing, emulsifying, cell disrupting, etc. Sharply machined teeth on the rotor interact with the sharply machined slots in the stator to perform the homogenizing action as the sample is drawn into the assembly and violently propelled through the stator slots. And that’s how it works!
Remember to clean homogenizers thoroughly after they are used and especially when changing samples.
How do you employ homogenizers in your research lab? Please share tips that help increase efficiency.