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, H(2)SO(4), or HNO(3) 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 mug ml(-1) for calf thymus DNA, 0.05-60.0 mug ml(-1) for fish sperm DNA, and 0.6-90.0 mug ml(-1) for yeast RNA. The detection limits (3sigma) 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.