Investigation of Interaction of Proflavine and Naphthol Red in Nucleic Acids by Light‐Absorption Spectrometry

Abstract

The formation of the double electrostatic films in nucleic acid will cause the aggregation of small molecules on it by a non‐covalent bond. The interaction of the dyes: proflavine (PLV) and naphthol red (NR) with nucleic acids [calf thymus (ct) DNA and yeast (y)RNA] in acidic medium was investigated by the microsurface adsorption–spectral correction (MSASC) technique. Results showed that the aggregation of PLV and NR on DNA and RNA agrees with the Langmuir isothermal adsorption. The maximal binding numbers of PLV is 0.85 with ctDNA‐P and 0.50 with yRNA‐P and those of NR 0.12 with ctDNA‐P and 0.07 with yRNA‐P. Their binding constants K are 8.13 × 104, 2.15 × 105, 2.20 × 105, and 2.05 × 105, respectively. The effect of ionic strength and temperature on the aggregation was made. The aggregation of PLV and NR in nucleic acids has been tried to apply to the quantitative detection of nucleic acids.