[Studies and application of the interaction of pentamethyl-p-rosaniline hydrochloride 6B and nucleic acids system].

A cationic dye pentamethyl-p-rosaniline hydrochloride 6B was used as a chromic probe and its binding reaction with nucleic acids was studied. In the weak alkalescent medium, the cationic dye showed a decrease in absorption at its maximal absorption peak (584.5 nm) on binding to nucleic acids. Based on this fact, a new UV-Vis spectrophotometric method for the determination of nucleic acids has been developed. Effects of ion-intensity, surfactant and organic solvent were investigated to establish optimum reaction conditions, and then nucleic acids were detected with quantitative analysis. The calibration curves of nucleic acids such as hs-DNA, smDNA, ct-DNA and yeast-RNA were linear over the ranges 0.50-4.00 microg x mL(-1), 0.20-5.00 microg x mL(-1), 0.20-5.00 microg x mL(-1) and 0.20-4.50 microg(-1) x mL(-1), respectively. The detection limits (3sigma/K) were 0.082, 0.037, 0.038 and 0.041 microg x mL(-1). In applications to quantitative analysis of nucleic acids synthesis samples, the recoveries of DNA or RNA ranged from 93.5% to 105.0%. Furthermore, the mechanism of interaction of pentamethyl-p-rosaniline hydrochloride 6B and nucleic acids system was also discussed.