pan-assay interference compounds pan-assay interference compounds pan-assay interference compounds (pains) are chemical compounds that often give false positive results in high-throughput screens. pains tend to react nonspecifically with numerous biological targets rather than specifically affecting one desired target. a number of disruptive functional groups are shared by many pains. diagram depicting a representative pan-assay interference compound. the drug-like molecule specifically interacts with target b, but the pains-like compound non-specifically interacts with multiple targets while a number of filters have been proposed and are used in virtual screening and computer-aided drug design, the accuracy of filters with regard to compounds they flag and don't flag has been criticized. common pains include toxoflavin, isothiazolones, hydroxyphenyl hydrazones, curcumin, phenol-sulfonamides, rhodanines, enones, quinones, and catechols.