14145 IUPAC Gold Book - hit threshold 10.1351/goldbook.14145 14145 current 1 Minimum activity that defines actives in a primary screen. It is usually expressed as percentage of inhibition or stimulation relative to assay controls. A widely used hit threshold is \(\pu{50\%}\) inhibition. A more statistically meaningful and equally common threshold is three standard deviations from the mean. actives https://goldbook.iupac.org/terms/view/14105 primary screen https://goldbook.iupac.org/terms/view/14184 PAC, 2011, 83, 1129. 'Glossary of terms used in biomolecular screening (IUPAC Recommendations 2011)' on page 1143 (https://doi.org/10.1351/PAC-REC-09-05-03) https://goldbook.iupac.org/terms/view/14145/html https://goldbook.iupac.org/terms/view/14145/json https://goldbook.iupac.org/terms/view/14145/plain Citation: 'hit threshold' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.14145 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-06-27T15:20:51+00:00