A surfactant enhanced stopped-flow kinetic fluorimetric method for the determination of trace DNA

A novel and high-sensitive stopped-flow kinetic fluorimetric method for determining the concentration of DNA (calf thymus DNA), in the presence of SDS, based on monitoring the variation of fluorescence within a very short period has been developed. The optimum conditions for various parameters, on which the binding of YOYO-1 to DNA depends, were investigated. It was found that the initial reaction rate increased linearly with increasing DNA concentration in the range from 8.0 × 10−10 to 9.0 × 10−8 M. The detection limit was calculated to be 3.0 × 10−10 M. This method was used for determining the concentration of DNA in synthetic samples and real samples extracted from leaves of Arabidopsis thaliana, tobacco and rice with satisfactory results. The kinetics of the interaction under pseudo first-order conditions was established by the aid of single-mixing stopped-flow techniques.