NBD chloride (4-Chloro-7-nitrobenzo-2-oxa-1,3-diazole) is nonfluorescent until it reacts with primary or secondary amines to produce a fluorescent product. NBD chloride has been extensively used as a derivatizing reagent for chromatography analysis of amino acids and low molecular weight amines. &lamba;Ex/&lamba; Em(MeOH) = 465/535 nm (for reaction product with primary amines); 485/540 nm (for reaction product with secondary amines) Yellow solid soluble in DMF Store at -20°C and protect from light C6H2ClN3O3 MW: 199.55