14136 IUPAC Gold Book - fluorescence polarisation assay 10.1351/goldbook.14136 14136 current 1 Assay in which the association between an intrinsically fluorescent ligand, or a ligand linked to a fluorescent probe, and a larger macromolecule is detected. The degree to which the labeled ligand depolarizes plane-polarized light is directly proportional to the rate at which it tumbles in solution. Tumbling will be slower when the ligand is associated with the larger macromolecule as compared to free in solution, consequently resulting in a lower degree of depolarization. fluorescence polarization https://goldbook.iupac.org//terms/view/14135 homogeneous binding assay https://goldbook.iupac.org//terms/view/14147 PAC, 2011, 83, 1129. 'Glossary of terms used in biomolecular screening (IUPAC Recommendations 2011)' on page 1141 (https://doi.org/10.1351/PAC-REC-09-05-03) https://goldbook.iupac.org/terms/view/14136/html https://goldbook.iupac.org/terms/view/14136/json https://goldbook.iupac.org/terms/view/14136/plain Citation: 'fluorescence polarisation assay' 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.14136 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. 2026-06-28T12:25:40+00:00