How to Sterilize a Lab Homogenizer

Sterilizing is one of several ways scientists can inactivate potentially infectious agents from laboratory equipment such as homogenizers and flow through chambers by the application pressure and steam.  The process can be accomplished in a sealed container called an autoclave using, for example, temperatures to 121⁰C and pressures to 15 psi for 60 minutes.  Certain precautions should be taken to help ensure removal of sample residues prior to sterilizing the homogenizer components and to avoid potential heat damage to bearings and seals in the shafts.

Pre-Clean Prior to Sterilizing

It’s important to realize that sterilizing is not the same as pre-cleaning and scrubbing.  Residues from samples being homogenized must be removed from rotor-stator generator assemblies and from the internal components of flow-through chambers.  This can be done by disassembly then rinsing components in water followed by carefully scrubbing them with a brush in a disinfecting solution.  We emphasize carefully because the rotors and stators have sharply machined edges.  These could provide a source of infection due to cuts suffered by lab personnel.

More thorough pre-treatment of components is accomplished in an ultrasonic cleaner where cavitation action accesses all surfaces in the ultrasonic cleaning solution to blast away contaminants.  Without the pre-cleaning step substances remaining on the components could be “baked on” the surface by the heat of the autoclave and be more difficult to remove.

Prepping Homogenizer Components for Sterilizing

Whether cleaning a rotor-stator generator and shaft or a flow through chamber the homogenizer must be disconnected from the drive motor.  Homogenizer drive shafts used to operate flow-through chambers have seals and bearings to prevent media from entering the drive shaft.   Unless specially specified these components can be compromised by the pressure and temperature of the autoclave.   Small flow through chambers such as the CAT DK30 can be safely autoclaved after removal from the drive shaft.  The larger DK40 chambers have O-rings on chamber lid/stator assemblies.  These should be examined frequently for deterioration due to heat and pressure.

In summary, for best results we strongly recommend pre-cleaning homogenizer and flow-through chamber components by disassembling them to allow the cleaning media full access to all surfaces.  Once gross contaminants are removed they then can be sterilized in an autoclave then reassembled.

If you’d like additional information on this topic please visit our cleaning tips post for lab homogenizers or feel free to ask us a question.

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