Use of a Fluorometric Imaging Plate Reader™ in high-throughput screening

High-throughput screening (HTS) efforts at Abbott Laboratories have been greatly facilitated by the use of a Fluorometric Imaging Plate Reader(TM) (FLIPR(TM); Molecular Devices, Sunnyvale, CA). The FLIPR(TM) (FLIPR) consists of an incubated cabinet with integrated 96-channel pipettor and fluorometer. An argon laser is used to excite fluorophores in a 96-well microtiter plate and the emitted fluorescence is imaged by a cooled CCD camera. The image data is downloaded from the camera and processed to average the signal from each well of the microtiter plate for each time point (up to 300 time points). The data is presented in real time on the computer screen, facilitating interpretation and trouble-shooting In addition to fluorescence, the camera can also detect luminescence from firefly luciferase. At Abbott, we have found that whole-cell assays show a substantially higher compound discovery rate compared to other screen formats. HTS using whole cell assays is advantageous in that it provides function-based information regarding compound activity in the primary screen. This is highly beneficial especially when receptor function is activated by ligand binding. Information about a compound's effect on a target provides a head-start for secondary assays that further characterize compound activity. In addition, fluorescence-based assays are the most successful in discovering compounds of interest for follow-up investigations. We have used the FLIPR for the screening of Abbott's compound collection through various targets in a whole-cell format. The targets screened have included hormone receptors and ion channel receptors. We will present an overview of the FLIPR instrument, provide some strategies for the use of the FLIPR, and discuss the impact, of FLIPR in Abbott's I-ITS efforts.