A Robotic Platform for Quantitative High-Throughput Screening

Abstract

High-throughput screening (HTS) is increasingly being adopted in academic institutions, where the decoupling of screening and drug development has led to unique challenges, as well as novel uses of instrumentation, assay formulations, and software tools. Advances in technology have made automated unattended screening in the 1536-well plate format broadly accessible and have further facilitated the exploration of new technologies and approaches to screening. A case in point is our recently-developed quantitative high-throughput screening (qHTS) paradigm which tests each library compound at multiple concentrations to construct concentration-response curves (CRCs) generating a comprehensive data set for each assay (Inglese et al, Proc. Natl. Acad. Sci USA 103, 11473–11478). The practical implementation of qHTS for cell-based and biochemical assays across libraries of >100,000 compounds (e.g. between 700,000 –2,000,000 sample wells tested) requires maximal efficiency and miniaturization, and the ability to easily accommodate many different assay formats and screening protocols. Here, we describe the design and utilization of a fully-integrated and automated screening system for qHTS at the NIH Chemical Genomics Center. We report system productivity, reliability, and flexibility, as well as modifications made to increase throughput, add additional capabilities, and address limitations. The combination of this system and qHTS has lead to the generation of over 6 million CRCs from >120 assays in the last three years, and is a technology that can be widely implemented to increase efficiency of screening and lead generation.

High-resolution dose–response screening using droplet-based microfluidics

“…In the future, we believe that it should be possible to increase throughput to 1 compound every 10 s by using a faster autosampler and a higher flow velocity in the capillary, without significantly reducing data quality (SI Appendix, Table S5). This rate would approach microplate-based quantitative high-throughput screening in terms of speed (3,40), while consuming approximately 1 μl of assay reagents (approximatley 2 orders of magnitude less) and yielding, on average, 700 data points per curve (approximately 2 orders of magnitude more). Although Taylor-Aris dispersion can be used to generate any concentration from zero to approximately 100% of the starting concentration (see SI Appendix), in practice the concentration range of each dose-response profile is limited by the dynamic range of the optical detection system in quantifying the concentration encoder.…”

The pharmaceutical industry and natural products: historical status and new trends

“…Undoubtedly, in industry HTS automation is the likely means of targeting bioactivity whilst in many academic institutions due to limitations in funding, HTS is not generally used inhouse and often requires outsourcing with limitations to the number of possible biological screens. Of course, utilizing modern techniques of HTS at least in theory, can lead to the identification of NCEs and hits, but the serendipity behind analyzing a less uncommon terrestrial or marine organism should not be overlooked (Michael et al 2008;Frearson and Collie 2009;Macarrón et al 2011).…”

Development of an Automated, High-Throughput Bactericidal Assay That Measures Cellular Respiration as a Survival Readout for Neisseria meningitidis

“…A serum normalization control series that lacks bactericidal activity against the strain of interest was included in each experiment to monitor the effect of serum quenching of resorufin. At hourly intervals, the plate was removed from the incubator and read to detect the fluorescence signal generated when resazurin is reduced to resorufin by bacterial respiration using a fully automated robotic platform built by GNF Systems (11). The data were collected for 16 h and then analyzed for titer determination in a three-step process.…”