[Determination of nucleic acids using toluidine blue as a fluorescence probe].

A new fluorimetric method has been developed for the determination of deoxyribonucleic acid (DNA) with toluidine blue (TB) as a fluorescence probe. It is based on the fluorescence quenching of toluidine blue in the presence of DNA. In Tris-HCl buffer solution (pH 8.5), the calibration graph was linear over the range 0.10-6.00 microg x mL(-1) for ctDNA, and the detection limit was 27 ng x mL(-1). The result of the determination of DNA of camphor tree's leaf by this method was satisfactory.