The PDE3B Assay Kit is designed for identification of PDE3B inhibitors using fluorescence polarization. The assay is based on the binding of a fluorescent nucleotide monophosphate generated by PDE3B to the binding agent. The key to the PDE3B Assay Kit is the specific binding agent. Using this kit, only two simple steps on a microtiter plate are required for PDE3B reactions. First, the fluorescently labeled cAMP is incubated with a sample containing PDE3B for 1 hour. Second, binding agent is added to the reaction mix to produce a change in fluorescent polarization that can then be measured using a fluorescence reader equipped for the measurement of fluorescence polarization.