Screening technologies that provide direct, rapid and reproducible results are critical to researchers in their search for potential PDE inhibitors. The IMAP® PDE FP; TR-FRET Evaluation kits are designed for use in biochemical in-vitro assays of phosphodiesterase activity. Kits provide both Fluorescein labeled cAMP and cGMP as possible substrates to evaluate the optimal configuration for the assay. The kits provide a protocol to run the assay with IMAP components for 800 data points. All that is needed is the PDE of choice.