Description_x000D_ General description_x000D_ Enteropeptidase (Enterokinase; EC 3.4.21.9) is an enzyme that converts trypsinogen to trypsin, the activity of which is required for the activation of chymotrypsin and procarboxypeptidases. It has an important role in food digestion and may serve as a marker of differentiated enterocytes and goblet cells._x000D_ Suitability_x000D_ Suitable for the measurement of enteropeptidase/enterokinase activity in biological samples or purified preparations._x000D_ Principle_x000D_ The Enteropeptidase/Enterokinase Activity Assay Kit is a rapid method to measure enteropeptidase activity in biological samples. Enteropeptidase activity is measured by cleaving a synthetic 7-amino-4-trifluoromethylcoumarin (AFC)-tagged peptide substrate containing the recognition sequence for enteropeptidase. This yields AFC, a fluorescent product (λex = 380/ λem = 500 nm), proportional to the enzymatic activity present. One unit of enteropeptidase is the amount of enzyme that generates 1.0 nmole of AFC per minute at room temperature.