[Study on the fluorescence spectra of LaL3 with DNA].

A fluorescence method is presented for the determination of DNA. The method is based on the interaction of LaL3 [L = morin (2', 3, 4', 5, 7-Pentahydroxyflavone), 2'-OH group deprotonated] with DNA in NH3 x H2O-NH4Cl buffer of pH = 8.0, with lambdaex at 387 nm, and lambdaem at 535 nm. Enhanced fluorescence was observed for LaL3 in the presence of DNA and in the presence of buffer solution of 10%(psi) and ethanol of 10%(psi). The linear range of determination was between 0 and 15 microg x mL(-1) 1 for DNA. The method proved to be simple, easy and sensitive for the determination of DNA. The mechanism of enhancing and the reasons for the effects of acid were also discussed.