The PDE3B Assay Kit is a fluorescence polarization (FP), homogeneous, 96-well assay kit designed for the screening and profiling of PDE3B (Phosphodiesterase 3B) inhibitors. This assay takes advantage of a specific fluorescent phosphate-binding nanoparticle. The kit contains enough purified recombinant PDE3B (amino acids 592-1112 (end) ), fluorescent probe, PDE assay buffer, Binding Agent, and diluent for 100 reactions.Figure 1: Illustration of the PDE3B Assay Kit principle.The assay uses a fluorescein-labeled cyclic adenosine monophosphate (cAMP-FAM for PDE3B), in which the phosphate group is engaged within the cyclic nucleotide. This is a very small molecule that rotates fast (low FP) . PDE3B catalyzes the hydrolysis of the phosphodiester bond in the cyclic nucleotide and frees the phosphate group. In a second step the free phosphate group is recognized by a specific phosphate-binding nanobead (Binding Agent) leading to the formation of a large complex, with restricted movement (high FP) . FP is proportional to PDE3B activity.This assay requires a fluorescent microplate reader capable of measuring fluorescence polarization (FP) and equipped with the required parts to read the FP signal. For more information FP technology, visit our Tech Note:FP, assay principles and applications.Note:As of November 2024, this protocol has been re-optimized for performance. Previous versions of this kit are available upon request.Need us to run inhibitor screens or profile your compounds against PDE3B? Check out ourPhosphodiesterase Screening Services.