Coenzyme A (CoA) functions as an acyl group carrier and carbonyl-activating group in a number of key biochemical reactions, including the TCA cycle and fatty acid metabolism. CoA is involved in over 100 different reactions in intermediary metabolism with approximately 4% of known enzymes utilizing CoA as a cofactor. Cayman's Coenzyme A Assay Kit can be used for assaying coenzyme A from plasma, serum, urine, cell lysates, and tissue homogenates. In this assay, CoA forms a complex with europium chloride and tetracycline in the presence of periodic acid. Fluorescence intensity of this complex is analyzed with an excitation wavelength between 380-390 nm and an emission wavelength between 610-615 nm.