Cleaning Tips for CAT Scientific Homogenizers
You’ve made a substantial investment in your rotor/stator homogenizer or emulsifier, so it is important that you maintain it to the highest standards, including cleaning the shafts and generator assemblies to avoid potential cross-contamination when processing different samples.
Cleaning is especially critical because of the complex shapes of generators – many of which have extremely fine stator slots and rotor geometries. Particles that lodge anywhere within these assemblies or become trapped in shafts must be completely removed if you are following current good laboratory practices (cGLP) or manufacturing practices (cGMP)before moving on to other sample preparation.
It is for these reasons that CAT Scientific includes maintenance and cleaning in the operations manuals for its line of CAT Modular Homogenizer Systems.
Basic Homogenizer Cleaning Recommendations
After each use homogenizer shafts and generator assemblies (i.e. the rotor and stator) should be cleaned by operating the unit in a solvent to dissolve residues of the processed material. This avoids clogging that can occur if the material dries in place. Use solvents that do not harm the gaskets.
Chemical sterilization using general-purpose disinfectants such as alcohol and formalin is always a good idea but be sure to remove chemical residues by operating the unit in sterilized water and allowing it to dry.
While both of the above processes can be accomplished with the generator attached to the driver unit removal of the generator assembly from the CAT homogenizer driver will be necessary if your operating procedures call for sterilizing with moist heat. This can be accomplished with a steam jet pressurized to 2 bars (~29 psi) at 120?C (248?F). Use caution in disassembly and reassembly as generators have sharp edges.
Ultrasonic Cleaning your CAT Homogenizing Tool
If cleaning with a disinfectant and steam jet is not thorough enough to dislodge and remove adherent particles consider using an ultrasonic cleaner for complete contaminant removal.
This cleaning method is included in World Health Organization (WHO) and the Association of periOperative Registered Nurses (AORN) recommendations for cleaning surgical instruments to control infection healthcare facilities. It can serve as a guideline for homogenizer and emulsifier shafts and generator assemblies when exceptional cleanliness is required.
The cleaning takes place in a stainless steel tank filled with a biodegradable cleaning solution as recommended by the cleaner manufacturer. The unit consists of a generator powering transducers mounted on the tank. When activated the transducers create billions of minute bubbles in the solution that implode on contact with shafts, rotors and stators immersed in the solution. Called cavitation the process quickly and safely blasts away any and all contaminants on components wetted by the solution. Yet the process does not damage delicate parts.
A Simple Homogenizer Cleaning Operation
After samples have been prepared the homogenizer shaft and generator should be pre-cleaned by operating the unit in a solvent as noted above. Then remove the generator and shaft assembly from the drive unit. If they are to be stored for batch cleaning immerse them in a sterile solution such as an enzyme soak to prevent residual contamination from drying on them.
Follow the equipment manufacturer’s operating instructions and recommendations on preparing cleaning solutions. In brief the process is as follows:
- When you’re ready to clean the emulsifier shaft and generator assemblies place them in the mesh basket that comes with the ultrasonic cleaner. If you disassemble the shaft and generator into its sub-components you can place these smaller parts in a fine screen immersion basket. Turn the unit on and, if equipped, set its timer for 10 minutes.
- Lower the components into the solution. At the end of the cycle remove the basket and check for cleanliness. If more cleaning is required reorient parts in the basket and replace them in the solution.
- When cleaning is complete remove the components and rinse them in water.
Depending on your cleaning protocols the components may have to be either disinfected or sterilized before being reattached to the drive units.
A benchtop cleaning unit operating at a frequency of 37,000 cycles per second (37 kHz) is ideal for cleaning homogenizer shafts and generators. Check with vendors for recommendations on equipment size, frequency and cleaning solution formulations that best meet your requirements.