The Tip of the Iceberg: How Pipette Tips Influence Results
Muriel Art, Vincent Dufey, Eppendorf Application Technologies S.A.
Ulrike Gast, Eppendorf SE
The fact that a tip fits onto a pipette cone does not say anything about the performance of the pipetting system comprising the components "Pipette and Tip". We performed a study including standard tips from 15 different manufacturers in order to investigate the tip-related influence on the pipetting result. The study results showed a dramatic influence of the tip on the pipetting accuracy.
The standard ISO 8655:2002 recommends using pipette and tips from the same supplier. Our study results emphasize the validity of this recommendation and the need of calibration/pipette adjustment if other tips than recommended by pipette suppliers are to be used.
Within the scientific community, a rising number of published experiments cannot be reproduced by other groups. In general, plastics are not taken seriously leading to problems with analysis results caused by e.g. leachables or incorrect pipetting volumes. This may lead to results not being reproducible if performed by other groups using other consumables.
Some problems with pipette tips are obvious, e.g. the need to push tips with force onto the pipette cone in order to achieve efficient tip fit. Other problems often remain unrecognized like decreased pipette accuracy when using other tips than recommended by the pipette supplier.
The ISO 8655-2:2002 standard defines pipette and tip as a system, which requires extra calibration for the use of other manufacturers' tips. But why does this standard put so much focus on a product that is to be discarded after usage?
This series of articles answers this question. It shows the influence of tips on the pipetting result explaining the main tip-related impact factors.