Abstract: A method for screening candidate compounds for an ability to modulate the biological activity of a target. The method includes the steps of providing a substrate comprising a target and an indicator, the substrate adapted for receiving a plurality of candidate compounds; contacting the substrate with a plurality of candidate compound samples in a manner wherein an identity of each candidate compound can be determined and wherein the candidate compounds in the candidate compound samples interact with the target in the substrate; detecting a signal, the signal produced by the indicator upon interaction between the target and a candidate compound; and identifying a candidate compound as a modulator of the biological activity of the target based upon an amount of signal produced.