Effect of liquid-handling accuracy on assay performance.

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.

Verifying liquid-handler performance for complex or nonaqueous reagents: a new approach.

Multichannel volume dispensing devices, such as automated liquid handlers, are widely used in drug discovery assays and other high-throughput screening processes. The performance of these systems is heavily based on the ability to deliver proper volumes of specific reagents. Discussed herein is the recent research on broadening existing methods for accurately assessing liquid-handler performance when dispensing complex or nonaqueous reagents. Accurate and reliable adjustment of liquid-handler protocols for varied reagent types could have far-reaching adoption in all scientific communities.