BioVision’s ATP Colorimetric and Fluorometric Assay kit is designed to be a robust, simple method which utilizes the phosphorylation of glycerol to generate a product that is easily quantified by colorimetric (OD 570 nm) or fluorometric (Ex/Em = 535/587 nm) methods. fluorometric assay). ATP concentration is determined by phosphorylating glycerol, resulting in a colorimetric (570 nm) or fluorometric ( ex = 535/ em = 587 nm) product proportional to the amount of ATP present. Note: The fluorometric assay is 10–100 times more sensitive than the colorimetric assay.