Errors Associated with Pipetting of Warm and Cold Liquids
By Carle, B., Rumery, D., Davis, A., Rodrigues, G. | Poster
Many common laboratory procedures require the handling and quantitative dispensing of reagents at various temperatures. Mechanical action micropipettes are most often used for this routine task. The construction of these pipettes, however, makes their performance susceptible to variations in temperatures of the samples dispensed. This susceptibility to thermal effects is reflected in pipette calibration standards (i.e. ISO 8655-6 and ASTM E1154), stipulating stringent control of temperatures (20 ± 0.5 oC) during pipette calibration, and also requiring that all materials, including the liquids, be thermally equilibrated prior to the calibration.
However, many common assay protocols require the dispensing of reagents that are not in the specified temperature equilibrium. Two common examples are tissue culture applications, which employ reagents and buffers at 37 oC, or assays with nucleic acid-based reagents at 4 oC or lower.
The work presented herein investigates the accuracy of micropipettes from three different manufacturers, in the most commonly used range of 2 mL to 1000 mL, when used to pipet aqueous samples at various temperatures.