Antimicrobial properties of Thermo
Scientific Finnpipette F1 compared to
LHC Research Group, Thermo Fisher Scientific, Vantaa, Finland
In this application note the antimicrobial
properties of the Thermo Scientific Finnpipette
F1 were compared to traditional pipettes without
antimicrobial treatment. The experiments were
performed by an independent laboratory (Institut
für Biotechnische Forschung und Entwicklung Graf
GmbH, Kirkel-Limbach, Germany).
Even when a pipette user observes strict cleanliness,
microbes from his or her hands may contaminate
the pipette and cause deterioration of is parts.
More importantly, these microbes are a potential
source of sample cross-contamination. Crosscontamination
can lead to false positive results
in diagnostic tests or incorrect results in scientific
To minimize these possibilities, the handle and the
dispensing button of the Finnpipette® F1 are made
of an antimicrobial polymer,to protect the device
from microbial growth.
In these experiments the antimicrobial properties of
the Finnpipette F1 were compared to three pipettes
without antimicrobial treatment.
Materials and Methods
The test pipettes were the Finnpipette F1
and traditional pipettes from three different
Two different approaches were used to determine
This method simulated pipette use:
The handles of the pipettes were disinfected
with 70% ethanol.
The handles were sampled for bacteria
using contact plates (Oxoid Dip Slides with TTC
(red spot) medium).
Each pipette was held bare-handed for one
The handles were then sampled for bacteria
using contact plates.
: The handles were sampled again
after four hours.
The contact plates were incubated at
37 °C for 24 hours. Microbial growth
was checked after the incubation period.
The pipettes were tested according
to ASTM standard E 2180, which
comprises a test method to evaluate
the antimicrobial effectiveness of agents
incorporated or bound into or onto
primarily flat hydrophobic or polymeric
surfaces. The test organisms used were
the two bacteria Escherichi coli and
The handles of the pipettes were
disinfected with 70% ethanol.
: Contamination was carried out
by pipetting droplets of 25 μl of the cell
suspension on the handles’ surfaces.
:The pipettes were stored in a
horizontal position while the suspensions
completely dried (approx. 60 minutes).
The number of colony forming
units (cfu, a measure for viable cells) was
determined after 30 minutes and after four
Results and discussion
The results of the simulation experiment (Method
1) are shown in the following pictures (Fig. 1-3).
The figures show that the Finnpipette F1 had
significant antimicrobial properties when compared
to competitive pipettes without antimicrobial
treatment. More bacteria were inactivated on the
handle of the Finnpipette F1 than on the handles of
the competitive pipettes.
The results of the ASTM standard testing experiment
(Method 2) are illustrated in the following graph
(Fig. 4). Four hours after the handles were
contaminated with bacterial suspensions, the reduction of E. coli was 99.9% for the Finnpipette
F1, and 98.3 to 99% for the competitor pipettes.
The reduction of S. aureus was 19% for the
Finnpipette F1 after four hours, while the reduction
was approximately 9% for the competitive pipettes.
Staphilococci are known to be relatively resistant to
drought stress and low water activities as occurred
due to the experimental conditions.
These results were consistent with with those of
the first experiment: the reduction of bacteria was
highest with the Finnpipette F1, followed by the
competitive pipette # 3.
Under dry conditions, pipette handles are not a
good base for microbial growth as seen by the
reduction of the number of viable microorganisms
on all pipettes. This is most probably due to drought
stress on the bacteria. The reduction, however, was
clearly higher for the Finnpipette F1 than for the
other test pipettes. The surface of the Finnpipette
F1 has a smooth finish while the other pipettes have
a textured surface. This may mean that also the
surface texture has an impact on the reduction of
These results show that the antimicrobial material
used in the handle and dispensing button of the
Finnpipette F1 resulted in a significant reduction of
microorganisms as compared to competitor pipettes
of leading brands. Therefore, the experiments
demonstrated the efficacy of the antimicrobial
polymer in giving an extra protection against