Miniaturisation of a high throughput screening assay comparing air displacement and capillary-based nanolitre...

The miniaturisation of high-throughput screening (HTS) assays has been a widely debated and researched strategy with the aims of reducing screening costs and increasing speed while not compromising data quality. In this context, liquid handling technologies continue to be improved. A new and promising development is the emergence of nanolitre dispensers, which are capable of direct compound transfer to assay microplates. In this study, we investigated the miniaturisation of a HTS kinase assay and compared the real life performance of current state-of-the-art air displacement transfer technology (MiniTrak V System) and a capillary based nanolitre dispenser (CyBi-HummingWell). The robustness and effectiveness of the miniaturised assay formats were compared by testing staurosporine to generate dose-response curves and 340 previously identified active compounds. Using the MiniTrak device, assay miniaturisation was achieved from 18 microL to 6 microL in 384-well and 1536-well plate formats. Utilising the nanolitre dispenser, miniaturisation was performed down to 5 microL in 1536-well plates. The Z' factors obtained for each assay format were consistently above 0.5. The data presented here describe the reproducibility of the results obtained with the two transfer technologies and highlight possible issues for hit identification.