How to Use Lab Homogenizers
As with all precision scientific equipment, laboratory homogenizers have advantages and limitations. Many of the questions we get at CAT Scientific come down to the improper use of lab homogenizers or misconceptions of what they do and what they should not be expected to do. For that matter, we could have titled this post “How NOT to Use Lab Homogenizers” but we like to take a positive approach.
Laboratory Homogenizer 101
(Move to the next if you are an expert.) A laboratory homogenizer is a controllable-speed tool designed to blend, emulsify, suspend, cut up, disrupt or otherwise process samples. These homogenizers are used primarily in product development research across a wide range of industries including animal, biology, food, plant, pharmaceutical and chemistry.
Components include a drive motor to which is attached a stationary drive shaft surrounding a rotor shaft powered by the drive motor. The business end, called the homogenizer generator, is a rotor and a stator designed to accomplish the homogenizing action in the sample. The entire assembly is attached to an adjustable mounting system that permits proper generator placement in the sample container, which can be a flask, beaker or test tube.
Homogenizer Performance Parameters
Here are points to consider for proper use of your laboratory homogenizer:
- Sample Size: The smaller the sample size the faster the homogenization. If you are dealing with costly or delicate samples you should select a generator designed for use in containers such as test tubes.
- Heat Build Up. The smaller the size the more susceptible the sample is to heat buildup. This may or may not be a problem but should be considered. If heat is a concern, regardless of sample size, consider slower homogenizing speed, short (3-5 second) cycles along with instant removal of the generator from the sample, or placing the sample container in a chilled container.
- Desired Particle Size: This is not to be confused with sample size. Homogenizer generator configurations can be specified to produce specific particle sizes. You may need to experiment here but generally a combination of correct homogenizer generator configuration, running speed and time should yield desired results.
- Sample Physical Properties: Lab homogenizers are precision instruments with precisely machined rotor and stator assemblies. They are not recommended for use with samples containing particles that damage the generator. Consider using an analytical mill such as the CAT AX 60 with its integrated cooling system to quickly pulverize samples to a size suitable for homogenizers.
- Cross contamination: OK this is not a “performance parameter” but it certainly has relevance when it comes to maintaining good laboratory practices. At CAT we continuously harp on this subject and therefore direct you to our post on cleaning homogenizers.