Phosphoenolpyruvate (PEP) is an important intermediate in carbohydrate metabolism. Containing a high-energy phosphate bond, PEP is involved in glycolysis and gluco-neogenesis and in the shikimate pathway as well as in carbon fixation in plants. Bacteria utilize PEP in the phosphor-transferase system to acquire sugars from the environment. In the glycolytic pathway, PEP is formed from 2-phosphoglycerate by enolase and generates ATP through the action of pyruvate kinase. BioVision’s PEP Assay Kit provides a convenient colorimetric and fluorometric means to measure PEP levels in various samples. In the assay, PEP is converted to ATP and pyruvate. The generated pyruvate is quantified by colorimetric (λmax = 570 nm) or fluorometric methods (Ex/Em = 535/587 nm). The assay is simple, sensitive and reliable. The detection limit is approximately 1 µM PEP in biological samples.