artifact assay Artifact (aka 'artefact') assays are performed to help interpret HTS results by testing whether a 'hit' might be due to some inherent physicochemical property of the compound or perturbagen alone - in the absence of any target. Examples include fluorescence, or inhibition of the enzyme luciferase, which are part of common assay designs; another example is solubility (e.g., if a compound aggregates and interferes with an assay readout). artefact assay physicochemical profiling assay counter screening assay