Eppendorf White Paper 14 User Manual

WHITE PAPER No. 14 I April 2013

Routine Maintenance of Centrifuges

Cleaning, Maintenance and Disinfection of Centrifuges, Rotors and Adapters

Samira Schroeder, Eppendorf AG, Hamburg, Germany

Executive Summary

In general, handling centrifuges is a safe process, as long
as high quality equipment is used, such as anodized or
PTFE coated aluminum rotors for instance, and the
following conditions are met: the centrifuges and their
equipment are used properly, are in an undamaged
condition and maintained as recommended here.
Prevention from long-term exposure to residues like salts
or aggressive chemicals through routine maintenance by
customers themselves can help to largely avoid extensive
corrosion incidents and to achieve the full lifetime of
equipment. Therefore, instructions how centrifuges and
their equipment can be cleaned, autoclaved, lubricated
and decontaminated by the user himself are presented
here. Finally, information is given in case professional

inspection and certication services are required in labs

with highest safety demands.

Introduction

Centrifuge maintenance, as the name says, is to be
understood as an everyday tool to maintain optimal condition
and safety of laboratory devices. To follow cleaning and
maintenance recommendations is highly important in case of
contamination with salts and chemicals. In case of long-term
exposure aggressive chemicals can develop corrosive spots
on rotors and rotor-buckets, which may constantly grow and
form small holes if ignored (Fig. 1). If small scratches and
cracks are already present on the rotor surface, this further
facilitates corrosion processes as protective coatings are
missing on those spots. In case of advanced corrosion,
rotors or buckets could be damaged in a way that makes
centrifugation processes unsafe. In worst case, damaged
rotors can even lead to a crash. Centrifuges manufactured
according to IEC standards ensure that no harm or damage
will be done to persons or surrounding lab equipment.
However the centrifuge and rotor themselves may be
destroyed.

High quality aluminum rotors and rotor-buckets are usually
protected against corrosion caused by commonly-used
laboratory chemicals, for instance by means of an anodized
coating. Nevertheless aggressive chemicals can still damage
the equipment! Such chemicals include concentrated and
mild alkalis, concentrated acids, solutions containing mercury
ions, copper ions and other heavy-metal ions, chlorinated
hydrocarbons, and concentrated saline solutions.
Normally steel rotors are protected against corrosion by
the use of coatings as well, but of course they also require
continuous care.
In addition contact with organic solvents (e. g. phenol,
chloroform) may have an adverse effect on transparent caps
(mainly manufactured from polycarbonate) of aerosol-tight
buckets.

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We recommend checking the rotors and rotor bores visually
for residue and corrosion on a weekly or monthly basis.
Rotors, buckets, lids or adapters, which have been subject
to chemical or mechanical damage or which have exceeded
their maximum operating life, should not be used any longer.
Damaged tubes or plates should not be centrifuged.
Important information regarding cleaning and maintenance
can not only be found in this paper, but also in the operating
manual of your centrifuge. If unsure about the cleaning or
decontamination methods of the centrifuge or rotor, one

Cleaning, Maintenance and Disinfection

Centrifuges

Remove buckets and rotor from the centrifuge. For
refrigerated centrifuges: Leave centrifuge lid open and
defrost the ice on the rotor chamber surface. If your
centrifuge is equipped with a water collection tray, empty

should contact the manufacturer and follow his
recommendation. If in doubt whether a rotor is still safe, an
authorized technician should be contacted.

Figure 1: Localized
corrosion in bore hole

and clean it, then wipe the rotor chamber with a moist
cloth. The outside of the centrifuge and the rotor chamber
should be cleaned regularly with a moist cloth and neutral
detergents (Fig. 2). Switch off the centrifuge, before you do so.

Figure 2: Wipe outside of centrifuge and clean rotor chamber and rotor with moist cloth and neutral detergents.

In the event of contamination caused by high-risk substances
(bio hazardous or aggressive chemical reagents and
radioactive reagents) wear a laboratory coat, gloves and

neutral agents for cleaning and disinfection (e.g. diluted
neutral alcohol-based disinfectant or 70 % isopropanol

mixture). Use a soaked gauze or lint-free cloth.
goggles. If there is broken glass: Retrieve the bigger broken
glass with forceps, remove small and powder shards with a
damp lint-free cloth. Absorb blood with gauze or paper towel
and subsequently, seal the material in a biohazard bag for
safe disposal (Fig. 3). Wipe the contaminated parts with

If necessary, remove still contaminated rotor, rotor lid, buckets,

and bucket caps out of centrifuge to decontaminate areas

which are difcult to access. After decontamination the

equipment should be wiped with distilled water.

Figure 3:
Decontamination
of centrifuge, rotor
and rotor buckets.

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Rotors, adapters, buckets and rubber seal

Use neutral cleaning solutions (alcohol or alcohol-based
disinfectant) and a soft cloth to clean your rotors and
accessories. Wipe contaminated parts with neutral agents
for cleaning and disinfection (e.g. diluted neutral alcohol­based disinfectant or 70 % isopropanol mixture). Use a
soaked gauze or lint-free cloth.
In case of spilling some aggressive liquid on your centrifuge
equipment, please clean it immediately. If there is stubborn
stain, clean with a plastic scrub pad and rinse equipment
with distilled water. Avoid immersing the rotor in water as

Figure 4: Clean rotor and rotor bores with plastic scrub pad and/or stiff test-tube brush in case of stubborn stain. Then rinse with water and dry.

liquid could ow into rotor cavities, and dry thoroughly with

a soft cleaning cloth.
As salt crystals located on metal surface will corrode the
surface, we strongly recommend cleaning rotors and buckets
immediately. If there is a need to clean the rotor’s tube cavities
or boreholes, use a stiff test-tube brush that has end bristles
and a non-metallic tip.
For swing-bucket rotors, ensure that the grooves in which

the buckets are tted are free of contamination. Take care to

ensure that the buckets can still swing freely.

After decontamination the equipment should be wiped with
distilled water. If needed, autoclave rotor, rotor lids and
buckets as recommended by the manufacturer. Never use
UV, beta, gamma radiation, or any high-energy radiation
source. Place parts on dry cloth upside down to dry (Fig. 4).

Caution:

Do not use acetone, caustic detergents, or detergents that contain chlorite ions. Corrosion is most frequently
caused by using chlorite ion solutions, such as sodium hypochlorite (household bleach). Do not use steel wool,
wire brushes, abrasives, or sandpaper, since they may damage the rotor coating (anodized coating) and thus
increase the risk for corrosion. We do not recommend usage of
aggressive cleaning agents used in these devices. These agents may result in corrosion.

Alternatively dry rotors, rotor boreholes and accessories
with absorbent towels. To prevent aerosol-tight lids/caps
and seals from getting worn out/damaged, store lids/caps
separately from the bucket/rotor.

dishwashers

for rotors or lids due to the