Flavin Adenine Dinucleotide (FAD) is a redox cofactor which plays an important role in metabolism. FAD exists in different redox states and cycles between FAD, FADH and FADH2. The primary sources of reduced FAD in eukaryotic metabolism are the citric acid cycle and the beta oxidation reaction pathways. In BioVision’s FAD Assay Kit, FAD functions as the cofactor of an oxidase which catalyze the formation of a product that reacts with OxiRed probe generating color and fluorescence. FAD can be detected by either colorimetric (λ=570 nm) or fluorometric (Ex/Em=535/587 nm) methods. The kit provides a rapid, simple, ultra-sensitive, and reliable test suitable for high throughput assay of FAD. The lower limit of detection is less than 1 nM FAD.