Interpretation of uniform-well readouts.

High-throughput screening (HTS) covers a range of measurements, from primary screens of either large libraries (>250 K) or small, focused collections (100-1,000 s) of test compounds, to secondary screens used to characterize the mechanism of action of a relatively small number of compounds. Data analysis of assay results from HTS relies upon assay performance and the control wells used to define the assay system. This chapter discusses parameters that must be considered when defining controls and plate maps for primary and secondary assays in HTS. Control wells and plate maps are suggested, which can gene-rally be applied toward a variety of biochemical and cellular assays. The controls and plate-map options can be matched to the scale of the screening campaign; examples are primary screens with % inhibition or % activation as endpoints or secondary screens with IC(50) or EC(50) values as endpoints.