The Tip of the Iceberg: How Pipette Tips Influence Results - Not Every Tip Tolerates Every Treatment
Muriel Art, Vincent Dufey, Eppendorf Application Technologies S.A.
Ulrike Gast, Eppendorf AG
The pipetting accuracy of pipette tips by certain manufacturers may suffer after autoclaving. This was not the case for Eppendorf tips. We describe the measures which Eppendorf takes in order to avoid the negative influences of autoclaving. Furthermore, we describe how the interference of biological assays by leachables from pipette tips is prevented. A MEA (Mouse Embryo Assay) test proves that sensitive biological systems are not influenced by Eppendorf pipette tips.
We have shown in part 1 and 2 of this series that pipette tips influence the performance of the system "pipette and tip" and thus the pipetting result. This was predominantly caused by the tip's shape and its production quality. Autoclaving is a widely applied method for decontamination of pipette tips but it imposes thermal stress. For this reason, calibration was used to determine whether autoclaving of pipette tips would influence the pipetting result. Recent scientific literature reported evidence of disturbance of a broad range of biological assays caused by leachables, even for pipette tips. Examples include enzymatic and photometric assays as well as alterations in growth rates in cell culture. Eppendorf does not make use of such additives and provides certificates to this effect. However, in order to obtain experimental proof, we have tested Eppendorf pipette tips for inhibition effects on the development of early stage embryos by performing a Mouse Embryo Assay.