Determination of DNA in Human Urine by Fluorescence Probe of Acridine Orange

Acridine orange has an equilibrium of aggregate forms in the presence of dodecylbenzene sulfonic acid sodium salt, but the equilibrium can shift when DNA is added to the system, thus leading to the enhancement of fluorescence intensity. The intensity shows a good linear relation with the concentration of the DNA in a certain range. Therefore, a new highly sensitive method for the determination of trace amount of DNA was developped. The maximum excitation and emission wavelengths are 506 and 529 nm, respectively, and the excitation slit and emission slit are both 5 nm. For the fish sperm DNA, the linear range of the determination is 0-10μg·mL-1, and the determination limit is 0.088μg·mL-1. The method has been successfully applied to the clinic determination of DNA in human urine.