Summary: The PhosphoSeek Technology for screening of kinase and phosphatase activities is a robust and homogeneous detection platform that measures the activity of a target enzyme. Assays are non-competitive with respect to substrate and do not require radioactive materials or secondary (detector) enzymes or antibodies. These biochemical assays are ideally suited for automated screening and can be read on any fluorometer. The Sensor is a proprietary fluorescent molecule that contains a trivalent metal ion, which binds to phosphorylated biological substrates. Phosphorylation is measured by the change of fluorescence of a dye-labeled and phosphorylated substrate when bound by the Sensor. The change in fluorescence directly correlates to the level of substrate conversion. When phospho-calibrator lipids are included in the experimental setup, the precise amount of product formation can be determined.