Spectrophotometric Determination of Nucleic Acids Using Dahlia Violet as Absorption Spectroscopic Probe

Abstract

In this paper, the binding reaction of Dahlia Violet and nucleic acids by the method of spectrophotometry is studied. At pH 6.1–6.9, the binding reaction is completed within 2 min at room temperature, and causes an absorbance decrease at the wavelength of the maximum absorption of the dye, i.e., 586 nm. Under optimum conditions, the calibration linearity for calf thymus deoxyribonucleic acid (ct DNA) and fish sperm deoxyribonucleic acid (fs DNA) are in the range of 0.4–11 µg mL⁻¹ and 0.4–13 µg mL⁻¹, respectively, and their detection limits are, correspondingly, 0.06 µg mL⁻¹ and 0.38 µg mL⁻¹. In addition, the binding number (n) of the dyes and DNA was studied by two methods: the molar ratio method and the graphical method of Rosenthanl. The values of n measured by the two methods are similar and each base pair of the nucleic acid can bind three molecules of Dahlia Violet. Moreover, the association constant (K) was estimated by the graphical method of Rosenthanl. Compared with some existing assays, the new method is sensitive, stable, simple, and relatively free from interference of co‐existing species. The analytical results of synthetic samples are satisfactory, with recoveries of 95.6%–102% and the relative standard deviations are lower than 4.2%.

Keywords:

• Nucleic acid
• Dahlia Violet
• Interaction
• Absorption spectroscopic probe
• Spectrophotometry

Acknowledgments

This work was supported by the National Natural Science Foundation of China (No. 50373017), the Nature Science Foundation of Shandong Province (Y2004B09), Science and Technology Program of Shandong Province (03C05) and Doctoral Startup Foundation of Jinan University (B0405), and all the authors express their deep thanks.