Gilson guide to pipetting - Emidio Albertini

chemical cleaning
n
This technique is used by Gilson for decontaminating pipettes returned for
service. The Pipetman is dismantled and fully immersed in an ultrasonic bath
with a detergent recommended for laboratory instruments. Next, the parts
are immersed in a virucidal, bactericidal and fungicidal solution. It is strongly
recommended to rinse the pipette with water and to dry thoroughly.
Note : A 2% formaldehyde solution is a common choice (CIDEX ® from Johnson
and Johnson). 10% Clorox ® has been recommended as a decontaminant for
elimination of DNA templates in the PCR laboratory*. However, while it is always
possible to find a liquid with the right properties to counter a given risk, no single
liquid can counter every risk.
UV radiation
n
Work surfaces may be decontaminated by exposure to 300nm UV light for
15 minutes. This method is not recommended for pipettes because, unlike
contaminating liquids or vapors, UV rays cannot penetrate inside the pipette.
beta ( b ) or gamma ( g ) radiation
n
This method is used by manufacturers for products sold under the label
“sterilized“. The penetrating rays are highly effective for the relatively inert
plastics used to manufacture pipette disposables. Costly and requiring special
installations, irradiation is reserved for producers of large quantities of
disposables.
Note : The choice of gamma or beta rays is determined by the type of plastic used to
manufacture the pipette or the disposable.
Ethylene oxide
n
Ethylene oxide and its reaction product ethylene chlorohydrin are highly toxic
and mutagenic. Therefore it is reserved for the sterilization of plastic materials
which may be altered by irradiation.
* A. Prince and L. Andrus, PCR : How to kill unwanted DNA, BioTechniques 1992, 12, 359-360.
PCR is a trademark of Hoffman LaRoche
Chapter 4
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