Determination of nucleic acids in acidic medium by enhanced light scattering of large particles

The large particle light scattering technique was first developed as a sensitive and convenient analysis method for microdetermination of nucleic acids by using a common spectrofluorometer. In 0.1 mol l−1 HCl, H2SO4, or HNO3 solution, the nucleic acids can aggregate to form large particles whose dimensions are comparable to the wavelength of UV-Vis light. The large particles can result in very strong light scattering which is well proportional to the concentration of nucleic acids in the range of 0.06–100.0 μg ml−1 for calf thymus DNA, 0.05–60.0 μg ml−1 for fish sperm DNA, and 0.6–90.0 μg ml−1 for yeast RNA. The detection limits (3σ) are 18.0 ng ml−1 for calf thymus DNA, 16.0 ng ml−1 for fish sperm DNA, and 57.6 ng ml−1 for yeast RNA, respectively. Six synthetic samples were determined with satisfactory results.