Category: Automation and High-Throughput Technologies
Ultra-high-throughput screening (uHTS) demands homogeneous assay formats to leverage the density of 1536/3456 well plates to increase the throughput of large compound (> 1 million) library screens against disease targets. Such assay formats require automated reagent dispensing and rigorous assay development. The key liquid handlers in any uHTS system are non-contact reagent dispensers rather than tip-based multi-channel pipetting devices that are common in many lower throughput assay systems. Critical requirements for any uHTS reagent dispenser are accuracy, precision, and speed. Additionally, it is important to integrate the uHTS dispenser into assay development as early as possible. For most bulk dispensers, this integration typically occurs late in the process. The Dragonfly® Discovery from TTP Labtech is a non-contact positive displacement dispenser designed to bridge dispensing needs from assay development through high-throughput screening. It provides ready access to 10 different reagents that can be dispensed in variable volumes as well as at high speeds. We evaluate the performance of this dispenser in high-throughput mode and examine its use in assay development for reagent concentration optimization in 1536-well plates and buffer component optimization by Design of Experiments (DOE).
Timothy Dawes– Sr Scientific Manager, Genentech, South San Francisco, California
Sr Scientific Manager
South San Francisco, California
For the last 25 years Timothy Dawes has worked in biotechnology starting as a post doctoral fellow at the University of California Santa Cruz where he received his PhD. in Physical Chemistry in 1990. He landed his first industrial position at Molecular Devices where he worked in collaboration with Biology, Engineering and Wafer Production to develop a high throughput version of the Cytosensor. The Cytosensor, a device built around a silicon chip based sensor to measure the extra-cellular pH of adherent cells. Timothy moved to Affymetrix to work on micro fluidic devices to process mRNA samples for the GeneChip microarrays. Chiron was Timothy’s next position where he worked for 9 years building the infrastructure for HTS, combinatorial Chemistry and CM. In 2006, Tim joined the small molecule drug discovery effort at Genentech, where he and the early leads group have put together an impressive 1536 uHTS screening system.