The use of the fluorescent acid chloride 5-dimethylaminonaphthalene-1-sulfonylchloride (dansyl chloride) is particularly suited to the separation and quantitation of polyamines by chromatographic techniques. Both the primary and secondary amino groups of polyamines are derivatized, giving a high fluorescence yield, and the derivatization reaction is quick and simple to perform. Using this method, polyamines can be detected and quantitated in many biological matrices, including cerebrospinal fluid, urine, blood, and tissue lysates (1 ,2 ); for CSF and urine this method can be used clinically (1 ). When combined with an acid hydrolysis step (1 ,3 ), reproducible results can be obtained for both free and conjugated polyamines (1 ,4 ).