This study illustrates how optimization of both liquid-handling accuracy and precision is critical to assay performance. The study was designed to examine (1) liquid-handling performance and (2) the effect of liquid-handling variability on two types of in vitro biochemical assays by making small but deliberate changes to assay volume delivery. Specifically, protein binding (streptavidin) and enzyme (α-galactosidase) assays were investigated by determining the effect of assay volume for each assay component. The concomitant effect of the liquid-handling variability was then measured via inhibitor potency and assay performance characteristics such as Z-factor, signal-to-background, and variability. It was found that small changes in assay component volumes were indeed measurable by potency (IC50) but not necessarily by assay variability (Z-factor). In fact, this study demonstrates how a miscalibrated liquid handler can lead to erroneous data.
The final, definitive version of this paper has been published in JALA, Journal of the Association for Laboratory Automation by SAGE Publications, Ltd., All rights reserved. ©