The fluorescence intensity of 2- p-toluidinylnaphthalene-6-sulphonate (TNS) is markedly increased by the addition of cyclodextrins. Mixtures of α- and β-cyclodextrins can be analysed by utilizing the difference in the sensitivity of fluorescent dyes for the two cyclodextrins. One method utilizes the fluorescence increment of TNS and the fluorescence decrement of o-anisaldehyde produced on binding with cyclodextrins. An alternative method relates the increase in TNS fluorescence to the total amount of cyclodextrins, which is determined from the reducing power after complete hydrolysis by Taka-amylase A (EC 3.2.1.1) and glucoamylase (EC 3.2.1.3).