DESIGN OF SIGNAL WINDOWS IN HIGH-THROUGHPUT SCREENING ASSAYS FOR DRUGDISCOVERY

High Throughput Screening (HTS) assays are used to rapidly identify pr omising drug candidates or leads from hundreds of thousands of compoun ds. Hence, it is important that the assay should be designed to discri minate responses from the active and inactive compounds and the backgr ound noise. We introduce the idea of a signal window which provides a degree of separation between signals. This allows one to correctly ide ntify new molecular entities with desired level of activity (called '' hits'') in the presence of variability, The statistical criteria for s etting and calculating signal windows are presented along with illustr ative examples, Results show that the ideal signal window should be 2 standard deviations (SD) of the largest signal in screening assays, al though a 1 SD window size is the minimum acceptable limit, When signal windows are set below 2 SD, the probability of missing ''hits'' incre ases significantly.