10.1177/1087057103258475ARTICLEJäger et al.Confocal Fluorescence Analysis Techniques AModular, Fully Integrated Ultra-High-Throughput Screening System Based on Confocal Fluorescence Analysis Techniques

The rapid increase in size of compound libraries, as well as new targets emerging from the Human Genome Project, require progress in ultra-high-throughput screening (uHTS) systems. In a joint effort with scientists and engineers from the biotech and the pharmaceutical industry, a modular, fully integrated system for miniaturized uHTS was developed. The goal was to achieve high data quality in small assay volumes (1-4 µL) combinedwith reliable and unattended operation. Two new confo-cal fluorescence readers have been designed. One of the instruments is a 4-channel confocal fluorescence reader, measuring with 4 objectives in parallel. The fluorescence readout is based on single-molecule detectionmethods, allowing high sensitiv-ity at low tracer concentrations and delivering an information-rich output. The other instrument is a confocal fluorescence im-aging reader, where the images are analyzed in terms of generic patterns and quantified in units of intensity per pixel. Both readers are spanning the application range from assays with isolated targets in homogenous solution or membrane vesicle-based assays (4-channel reader) to cell-based assays (imaging reader). Results froma comprehensive test on these assay types demonstrate the high quality and robustness of this screening system. (Journal of Biomolecular Screening 2003:648-659) Key words: integrated screening system, high-throughput screening, fluorescence, single molecule detection, confocal op-tics, homogenous assay, cellular assay, cell imagin