Resonance Light Scattering for the Determination of Nucleic Acids With Methyl Violet

For the first time, methyl violet (MV) was used to determine nucleic acids with a resonance light scattering (RLS) technique. The interactions of MV with nucleic acids give strong signals of RLS at 327.0, 490.0 and 651.0 nm. Based on this reaction, a new quantitative determination method for nucleic acids in aqueous solutions has been developed. At pH 7.51 and ionic strength 0.005 mol kg−1, with 4.0×10−5 mol l−1 of MV, linear relationships were found between the enhanced intensity of RLS at 651.0 nm and the concentration of nucleic acids in the range 0–3.0 μlg ml−1 for herring sperm DNA (hsDNA) and calf thymus DNA (ctDNA), 0–4.0 μlg ml−1for yeast RNA (yRNA). The limits of detection were 404.5 ng ml−1 for herring sperm DNA, 764.0 ng ml−1 for calf thymus DNA and 414.9 ng ml−1 for yeast RNA. The assay is proved to be convenient, rapid, inexpensive and simple.