Quantitative characterization of non-contact microdispensing technologies for the sub-microliter range

Abstract

This work describes how to effectively compare non-contact dispensing technologies for automated liquid handling under high-throughput screening (HTS) conditions in the range of 0.05-10 μl. Exemplarily, we characterize five established technologies and categorize them into valve-based and positive displacement-based technologies. Furthermore we introduce dispensing accuracy and precision in an 'intra-run', 'inter-run' and 'tip-to-tip' context as universally applicable performance parameters. A NIST traceable spectrophotometric measurement method is utilized for experimental characterization. It yields an Intra-Run CV (Inter-Run CV) between 0.4% to 7.7% (0.5 to 10.9%) and a Tip-to-Tip CV between 1.4% and 9.9% for target volumes <1 μl. An absolute accuracy of better than 5.0% is generally difficult to achieve in the sub-microliter range.